Chantal Marie Elisabeth Tallaksen

• Oender, Demet; Faber, Jennifer; Wilke, Carlo; Schaprian, Tamara; Lakghomi, Asadeh & Mengel, David [Show all 28 contributors for this article] (2023). Evolution of Clinical Outcome Measures and Biomarkers in Sporadic Adult-Onset Degenerative Ataxia. Movement Disorders. ISSN 0885-3185. p. 654–664. doi: 10.1002/mds.29324. Full text in Research Archive Show summary

  ABSTRACT Background Sporadic adult‐onset ataxias without known genetic or acquired cause are subdivided into multiple system atrophy of cerebellar type (MSA‐C) and sporadic adult‐onset ataxia of unknown etiology (SAOA). Objectives To study the differential evolution of both conditions including plasma neurofilament light chain (NfL) levels and magnetic resonance imaging (MRI) markers. Methods SPORTAX is a prospective registry of sporadic ataxia patients with an onset >40 years. Scale for the Assessment and Rating of Ataxia was the primary outcome measure. In subgroups, blood samples were taken and MRIs performed. Plasma NfL was measured via a single molecule assay. Regional brain volumes were automatically measured. To assess signal changes, we defined the pons and middle cerebellar peduncle abnormality score (PMAS). Using mixed‐effects models, we analyzed changes on a time scale starting with ataxia onset. Results Of 404 patients without genetic diagnosis, 130 met criteria of probable MSA‐C at baseline and 26 during follow‐up suggesting clinical conversion to MSA‐C. The remaining 248 were classified as SAOA. At baseline, NfL, cerebellar white matter (CWM) and pons volume, and PMAS separated MSA‐C from SAOA. NfL decreased in MSA‐C and did not change in SAOA. CWM and pons volume decreased faster, whereas PMAS increased faster in MSA‐C. In MSA‐C, pons volume had highest sensitivity to change, and PMAS was a predictor of faster progression. Fulfillment of possible MSA criteria, NfL and PMAS were risk factors, CWM and pons volume protective factors for conversion to MSA‐C. Conclusions This study provides detailed information on differential evolution and prognostic relevance of biomarkers in MSA‐C and SAOA. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

• Tallaksen, Chantal & Narverud, Sverre F. (2021). Shoshin beriberi. Tidsskrift for Den norske legeforening (Tidsskriftet). ISSN 0029-2001. 141(6), p. 1–2. doi: 10.4045/tidsskr.21.0215. Full text in Research Archive
• Roux, Thomas; Barbier, Mathieu; Papin, Mélanie; Davoine, Claire-Sophie; Sayah, Sabrina & Coarelli, Giulia [Show all 87 contributors for this article] (2020). Clinical, neuropathological, and genetic characterization of STUB1 variants in cerebellar ataxias: a frequent cause of predominant cognitive impairment. Genetics in Medicine. ISSN 1098-3600. 22(11), p. 1851–1862. doi: 10.1038/s41436-020-0899-x. Full text in Research Archive
• Prestsæter, Sjur; Koht, Jeanette; Lamari, Foudil; Tallaksen, Chantal; Hoven, Stian Tobias Juel & Vigeland, Magnus Dehli [Show all 8 contributors for this article] (2020). Elevated hydroxycholesterols in Norwegian patients with hereditary spastic paraplegia SPG5. Journal of the Neurological Sciences. ISSN 0022-510X. 419:117211, p. 1–4. doi: 10.1016/j.jns.2020.117211. Full text in Research Archive Show summary

  Spastic paraplegia type 5 (SPG5/HSP-CYP7B1) is an autosomal recessive hereditary spastic paraplegia (HSP) caused by biallelic variants in the CYP7B1 gene, resulting in dysfunction of the enzyme oxysterol-7-α-hydroxylase. The consequent accumulation of hydroxycholesterols in plasma seems to be pathognomonic for SPG5, and represent a possible target for treatment. We aimed to characterize Norwegian patients with SPG5, including clinical examinations, genetic analyses, measurements of hydroxycholesterols, electrophysiological investigations and brain imaging. Five unrelated patients carried presumed disease-causing variants in CYP7B1, three of the variants were novel. Four patients presented with pure HSP, one with complex HSP. The three tested patients all had markedly increased levels of 25- and 27-hydroxycholesterol in plasma. Our results suggest that the clinical examination is still the best approach to classify disease severity in patients with SPG5. Plasma hydroxycholesterols were elevated, thus presenting as potentially valuable diagnostic biomarkers, in particular in patients where genetic analyses are inconclusive. Keywords: CYP7B1; Hereditary spastic paraplegia; Hydroxycholesterols; Oxysterols; SPG5.

• Hikmat, Omar; Naess, Karin; Engvall, Martin; Klingenberg, Claus; Rasmussen, Magnhild & Tallaksen, Chantal [Show all 15 contributors for this article] (2020). Simplifying the clinical classification of polymerase gamma (POLG) disease based on age of onset; studies using a cohort of 155 cases. The Journal of Inherited Metabolic Disease (JIMD). ISSN 0141-8955. 43(4), p. 726–736. doi: 10.1002/jimd.12211. Full text in Research Archive Show summary

  Background Variants in POLG are one of the most common causes of inherited mitochondrial disease. Phenotypic classification of POLG disease has evolved haphazardly making it complicated and difficult to implement in everyday clinical practise. The aim of our study was to simplify the classification and facilitate better clinical recognition. Methods A multinational, retrospective study using data from 155 patients with POLG variants recruited from seven European countries. Results We describe the spectrum of clinical features associated with POLG variants in the largest known cohort of patients. While clinical features clearly form a continuum, stratifying patients simply according to age of onset—onset prior to age 12 years; onset between 12 and 40 years and onset after the age of 40 years, permitted us to identify clear phenotypic and prognostic differences. Prior to 12 years of age, liver involvement (87%), seizures (84%), and feeding difficulties (84%) were the major features. For those with onset between 12 and 40 years, ataxia (90%), peripheral neuropathy (84%), and seizures (71%) predominated, while for those with onset over 40 years, ptosis (95%), progressive external ophthalmoplegia (89%), and ataxia (58%) were the major clinical features. The earlier the onset the worse the prognosis. Patients with epilepsy and those with compound heterozygous variants carried significantly worse prognosis. Conclusion Based on our data, we propose a simplified POLG disease classification, which can be used to guide diagnostic investigations and predict disease course.

• Hikmat, Omar; Vederhus, Bente Johanne; Benestad, Merete Røineland; Engeset, Ida Malén Eun; Klingenberg, Claus & Rasmussen, Magnhild [Show all 10 contributors for this article] (2020). Mental health and health related quality of life in mitochondrial POLG disease. Mitochondrion (Amsterdam. Print). ISSN 1567-7249. 55, p. 95–99. doi: 10.1016/j.mito.2020.09.005. Full text in Research Archive Show summary

  We aimed to assess the impact of POLG disease on mental health and quality of life in 15 patients using the Symptom Checklist-90-R (SCL-90-R) and Short-Form 36 Health Survey (RAND-36). We found increased scores in all nine subscales of SCL-90-R, particularly phobic anxiety, depression and somatization. Further, patients reported considerably lower scores in all RAND-36 domains. This study revealed a global decline in mental health and poor quality of life in patients with POLG disease and highlights the need for increased awareness and systematic assessment in order to improve their quality of life and mental health.

• Hikmat, Omar; Naess, Karin; Engvall, Martin; Klingenberg, Claus; Rasmussen, Magnhild & Tallaksen, Chantal [Show all 16 contributors for this article] (2020). The impact of gender, puberty, and pregnancy in patients with POLG disease. Annals of clinical and translational neurology. 7(10), p. 2019–2025. doi: 10.1002/acn3.51199. Full text in Research Archive Show summary

  Objective: To study the impact of gender, puberty, and pregnancy on the expression of POLG disease, one of the most common mitochondrial diseases known. Methods: Clinical, laboratory, and genetic data were collected retrospectively from 155 patients with genetically confirmed POLG disease recruited from seven European countries. We used the available data to study the impact of gender, puberty, and pregnancy on disease onset and deterioration. Results: We found that disease onset early in life was common in both sexes but there was also a second peak in females around the time of puberty. Further, pregnancy had a negative impact with 10 of 14 women (71%) experiencing disease onset or deterioration during pregnancy. Interpretation: Gender clearly influences the expression of POLG disease. While onset very early in life was common in both males and females, puberty in females appeared associated both with disease onset and increased disease activity. Further, both disease onset and deterioration, including seizure aggravation and status epilepticus, appeared to be associated with pregnancy. Thus, whereas disease activity appears maximal early in life with no subsequent peaks in males, both menarche and pregnancy appear associated with disease onset or worsening in females. This suggests that hormonal changes may be a modulating factor.

• Lipka, Alexander F.; Boldingh, Marion; Zwet, Erik W. van; Schreurs, Marco W.J; Kuks, Jan B.M. & Tallaksen, Chantal [Show all 8 contributors for this article] (2019). Long‐term follow‐up, quality of life, and survival of patients with Lambert‐Eaton myasthenic syndrome. Neurology. ISSN 0028-3878. 94(5), p. e511–e520. doi: 10.1212/WNL.0000000000008747. Full text in Research Archive
• Stenshorne, Ida; Rasmussen, Magnhild; Salvanos, Panagiotis; Tallaksen, Chantal; Bindoff, Laurence & Koht, Jeanette (2019). Fever-related ataxia: A case report of CAPOS syndrome. Cerebellum & ataxias. 6:2, p. 1–5. doi: 10.1186/s40673-019-0096-3. Full text in Research Archive Show summary

  Background: CAPOS (Cerebellar ataxia, Areflexia, Pes cavus, Optic atrophy and Sensorineural hearing loss) syndrome is caused by the heterozygous mutation, c.2452G > A, in the ATP1A3 gene. Other mutations in this gene can cause a spectrum of overlapping phenotypes including alternating hemiplegia of childhood, rapid onset dystonia parkinsonism, early infantile epileptic encephalopathy and fever induced paroxysmal weakness and encephalopathy. The phenotype is still mistaken for mitochondrial/metabolic disorders and follow up studies are scare. Case presentation: We report a 20 year old Norwegian male with ataxia, sensorineural deafness and visual loss. Before the age of five he experienced three fever related episodes of acute neurological deterioration when he temporarily lost his acquired motor skills and developed persistent gait and limb ataxia. In childhood, he developed bilateral optic atrophy and bilateral sensorineural hearing loss. Motor skills improved and at age 20 the patient showed a mild ataxia, hearing loss and reduced vision. A c.2452G > A mutation in the ATP1A3 gene was identified and CAPOS syndrome was confirmed. Conclusions: This is the first Norwegian patient reported with CAPOS syndrome. Our patient had a de novo, previously identified ATP1A3 mutation. The combination of recurrent episodes of fever related ataxia, loss of motor skills in early childhood, and early onset hearing and vision loss is typical of CAPOS syndrome. Previous reports suggest a gradual progression of the disease after the initial episodes, while this patient showed a good outcome with improvement of motor skills from adolescence long after the last deterioration episode.

• Rydning, Siri Lynne; Koht, Jeanette; Sheng, Ying; Sowa, Piotr; Hjorthaug, Hanne Sagsveen & Wedding, Iselin Marie [Show all 12 contributors for this article] (2019). Biallelic POLR3A variants confirmed as a frequent cause of hereditary ataxia and spastic paraparesis. Brain. ISSN 0006-8950. 142:e12(4), p. 1–5. doi: 10.1093/brain/awz041. Full text in Research Archive
• Sjaastad, Ottar; Blau, Nenad; Rydning, Siri Lynne; Peters, Verena; Rødningen, Olaug Kristin & Stray-Pedersen, Asbjørg [Show all 9 contributors for this article] (2018). Homocarnosinosis: A historical update and findings in the SPG11 gene. Acta Neurologica Scandinavica. ISSN 0001-6314. 138(3), p. 245–250. doi: 10.1111/ane.12949. Full text in Research Archive
• Parodi, Livia; Fenu, Silvia; Barbier, Mathieu; Banneau, Guillaume; Duyckaerts, Charles & Montcel, Sophie Tezenas du [Show all 15 contributors for this article] (2018). Spastic paraplegia due to SPAST mutations is modified by the underlying mutation and sex. Brain. ISSN 0006-8950. 141(12), p. 3331–3342. doi: 10.1093/brain/awy285. Full text in Research Archive
• Hikmat, Omar; Naess, Karin; Engvall, Martin; Klingenberg, Claus; Rasmussen, Magnhild & Tallaksen, Chantal [Show all 13 contributors for this article] (2018). Elevated cerebrospinal fluid protein in POLG-related epilepsy: Diagnostic and prognostic implications. Epilepsia. ISSN 0013-9580. 59(8), p. 1595–1602. doi: 10.1111/epi.14459. Full text in Research Archive
• Coutelier, Marie; Hammer, Monia B.; Stevanin, Giovanni; Monin, Marie-Lorraine; Davoine, Claire-Sophie & Mochel, Fanny [Show all 35 contributors for this article] (2018). Efficacy of exome-targeted capture sequencing to detect mutations in known cerebellar ataxia genes. JAMA Neurology. ISSN 2168-6149. 75(5), p. 591–599. doi: 10.1001/jamaneurol.2017.5121. Full text in Research Archive
• Rydning, Siri Lynne; Dudesek, Ales; Rimmele, Florian; Funke, Claudia; Krüger, Stefanie & Biskup, Saskia [Show all 12 contributors for this article] (2018). A novel heterozygous variant in ERLIN2 causes autosomal dominant pure hereditary spastic paraplegia. European Journal of Neurology. ISSN 1351-5101. 25(7), p. 943–948. doi: 10.1111/ene.13625. Full text in Research Archive
• Samuelsson, Kristin; Radovic, Ana; Press, Rayomond; Auranen, Mari; Ylikallio, Emil & Tyynismaa, Henna [Show all 16 contributors for this article] (2018). Screening for Fabry disease and Hereditary ATTR amyloidosis in idiopathic small-fiber and mixed neuropathy. Muscle and Nerve. ISSN 0148-639X. 59(3), p. 354–357. doi: 10.1002/mus.26348. Full text in Research Archive
• Arntzen, Kjell Arne; Høyer, Helle; Ørstavik, Kristin; Tallaksen, Chantal; Vedeler, Christian A. & Østern, Rune André Helland [Show all 9 contributors for this article] (2018). Charcot-Marie-Tooth disease type 4C in Norway: Clinical characteristics, mutation spectrum and minimum prevalence. Neuromuscular Disorders. ISSN 0960-8966. 28(8), p. 639–645. doi: 10.1016/j.nmd.2018.06.004. Full text in Research Archive
• Giordano, Ilaria; Harmuth, Florian; Jacobi, Heike; Paap, Brigitte; Vielhaber, Stefan & MacHts, Judith [Show all 28 contributors for this article] (2017). Clinical and genetic characteristics of sporadic adult-onset degenerative ataxia. Neurology. ISSN 0028-3878. 89(10), p. 1043–1049. doi: 10.1212/WNL.0000000000004311. Full text in Research Archive
• Boldingh, Marion; Maniaol, Angelina; Brunborg, Cathrine; Dekker, Luuk; Lipka, Alexander F. & Niks, Erik Harmen [Show all 8 contributors for this article] (2017). Prevalence and clinical aspects of immigrants with myasthenia gravis in northern Europe. Muscle and Nerve. ISSN 0148-639X. 55(6), p. 819–827. doi: 10.1002/mus.25408. Full text in Research Archive
• Rydning, Siri Lynne; Backe, Paul Hoff; Sousa, Mirta; Iqbal, Zafar; Øye, Ane-Marte & Sheng, Ying [Show all 14 contributors for this article] (2017). Novel UCHL1 mutations reveal new insights into ubiquitin processing. Human Molecular Genetics. ISSN 0964-6906. 26(6), p. 1031–1040. doi: 10.1093/hmg/ddw391. Full text in Research Archive Show summary

  Recessive loss of function of the neuronal ubiquitin hydrolase UCHL1 has been implicated in early-onset progressive neurodegeneration (MIM no. 615491), so far only in one family. In this study a second family is characterized, and the functional consequences of the identified mutations in UCHL1 are explored. Three siblings developed childhood-onset optic atrophy, followed by spasticity and ataxia. Whole exome sequencing identified compound heterozygous variants in UCHL1, c.533G > A (p.Arg178Gln) and c.647C > A (p.Ala216Asp), cosegregating with the phenotype. Enzymatic activity of purified recombinant proteins analysed by ubiquitin hydrolase assays showed a 4-fold increased hydrolytic activity of the recombinant UCHL1 mutant Arg178Gln compared to wild type, whereas the Ala216Asp protein was insoluble. Structural 3D analysis of UCHL1 by computer modelling suggests that Arg178 is a rate-controlling residue in catalysis which is partly abolished in the Arg178Gln mutant and, consequently, the Arg178Gln mutant increases the enzymatic turnover. UCHL1 protein levels in fibroblasts measured by targeted mass spectrometry showed a total amount of UCHL1 in control fibroblasts about 4-fold higher than in the patients. Hence, studies of the identified missense variants reveal surprisingly different functional consequences as the insoluble Ala216Asp variant leads to loss of function, whereas the Arg178Gln leads to increased enzyme activity. The reported patients have remarkably preserved cognition, and we propose that the increased enzyme activity of the Arg178Gln variant offers a protective effect on cognitive function. This study establishes the importance of UCHL1 in neurodegeneration, provides new mechanistic insight about ubiquitin processing, and underlines the complexity of the different roles of UCHL1.

• Hikmat, Omar; Tzoulis, Charalampos; Klingenberg, Claus; Rasmussen, Magnhild; Tallaksen, Chantal & Brodtkorb, Eylert [Show all 10 contributors for this article] (2017). The presence of anaemia negatively influences survival in patients with POLG disease. The Journal of Inherited Metabolic Disease (JIMD). ISSN 0141-8955. 40(6), p. 861–866. doi: 10.1007/s10545-017-0084-9. Full text in Research Archive
• Iqbal, Zafar; Rydning, Siri Lynne; Wedding, Iselin Marie; Koht, Jeanette; Pihlstrøm, Lasse & Rengmark, Aina Sylvia Haugen [Show all 9 contributors for this article] (2017). Targeted high throughput sequencing in hereditary ataxia and spastic paraplegia. PLOS ONE. 12:e0174667(3), p. 1–19. doi: 10.1371/journal.pone.0174667. Full text in Research Archive Show summary

  Hereditary ataxia and spastic paraplegia are heterogeneous monogenic neurodegenerative disorders. To date, a large number of individuals with such disorders remain undiagnosed. Here, we have assessed molecular diagnosis by gene panel sequencing in 105 early and late-onset hereditary ataxia and spastic paraplegia probands, in whom extensive previous investigations had failed to identify the genetic cause of disease. Pathogenic and likely-pathogenic variants were identified in 20 probands (19%) and variants of uncertain significance in ten probands (10%). Together these accounted for 30 probands (29%) and involved 18 different genes. Among several interesting findings, dominantly inherited KIF1A variants, p.(Val8Met) and p.(Ile27Thr) segregated in two independent families, both presenting with a pure spastic paraplegia phenotype. Two homozygous missense variants, p.(Gly4230Ser) and p.(Leu4221Val) were found in SACS in one consanguineous family, presenting with spastic ataxia and isolated cerebellar atrophy. The average disease duration in probands with pathogenic and likely-pathogenic variants was 31 years, ranging from 4 to 51 years. In conclusion, this study confirmed and expanded the clinical phenotypes associated with known disease genes. The results demonstrate that gene panel sequencing and similar sequencing approaches can serve as efficient diagnostic tools for different heterogeneous disorders. Early use of such strategies may help to reduce both costs and time of the diagnostic process.

• Horn, Morten Andreas; Müller, Karin Brigitte; Ferdinandusse, Sacha; Jørum, Ellen; Mellgren, Svein Ivar & Retterstøl, Lars [Show all 8 contributors for this article] (2016). Mild phenotype in an adult male with X‐linked adrenoleukodystrophy – case report. Clinical Case Reports. 4(2), p. 177–181. doi: 10.1002/ccr3.434. Full text in Research Archive Show summary

  Key Clinical Message X-linked adrenoleukodystrophy may present with a deceptively mild phenotype, even in adult males. Tight collaboration between clinicians, geneticists, biochemists, and other specialists is increasingly required for clarification of diagnosis in cases with atypical presentation.

• Gilhus, Nils Erik; Kerty, Emilia; Løseth, Sissel; Mygland, Åse & Tallaksen, Chantal (2016). Myasthenia gravis - diagnostikk og behandling. Tidsskrift for Den norske legeforening (Tidsskriftet). ISSN 0029-2001. 136(12/13), p. 1089–1094. doi: 10.4045/tidsskr.15.1259. Full text in Research Archive
• Jahic, Amir; ERICHSEN, ANNE KJERSTI; Deufel, Thomas; Tallaksen, Chantal & Beetz, Christian (2016). A polymorphic Alu insertion that mediates distinct disease-associated deletions. European Journal of Human Genetics. ISSN 1018-4813. 24(9), p. 1371–1374. doi: 10.1038/ejhg.2016.20. Full text in Research Archive
• Boldingh, Marion; Maniaol, Angelina; Brunborg, Cathrine; Weedon-Fekjær, Harald; Verschuuren, Jan J. G. M & Tallaksen, Chantal (2016). Increased risk for clinical onset of myasthenia gravis during the postpartum period. Neurology. ISSN 0028-3878. 87(20), p. 2139–2145. doi: 10.1212/WNL.0000000000003339. Full text in Research Archive
• Paap, Brigitte K.; Roeske, Sandra; Durr, Alexandra; Schöls, Ludger; Ashizawa, Tetsuo & Boesch, Sylvia [Show all 19 contributors for this article] (2016). Standardized Assessment of Hereditary Ataxia Patients in Clinical Studies. Movement Disorders Clinical Practice. 3(3), p. 230–240. doi: 10.1002/mdc3.12315. Full text in Research Archive
• Simonsen, Cecilia Smith; Celius, Elisabeth Gulowsen; Brunborg, Cathrine; Tallaksen, Chantal; Eriksen, Erik Fink & Holmøy, Trygve [Show all 7 contributors for this article] (2016). Bone mineral density in patients with multiple sclerosis, hereditary ataxia or hereditary spastic paraplegia after at least 10 years of disease - a case control study. BMC Neurology. 16. doi: 10.1186/s12883-016-0771-4. Full text in Research Archive Show summary

  Background Although disability is considered the main cause of low bone mineral density (BMD) in multiple sclerosis (MS), other factors related to the disease process or treatment could also be involved. The aim of this study was to assess whether patients with MS are more likely to develop low BMD (osteopenia or osteoporosis) than patients with the non-inflammatory neurological diseases Hereditary Spastic Paraplegia (HSP) and Hereditary Ataxia (HA). Methods We performed a case control study comparing BMD (spine, hip and total body) and biochemical measures of bone metabolism in 91 MS patients and 77 patients with HSP or HA, matched for age, gender and disability. Both patient groups had lived with the disease for at least 10 years. Results In total 74.7% of the patients with MS and 75.3% of the patients with HSP or HA had osteopenia (−2.5 < T- score < −1.0) or osteoporosis (T- score ≤ −2.5) in one or more sites. Osteoporosis was more common in patients with MS than with HSP/HA (44.0 vs 20.8%, p =0.001). This difference was not significant after correction for confounders (p = 0.07), nor were any of the biochemical markers. Conclusion Most patients with disabling neurological diseases like MS and HSP/HA develop osteopenia or osteoporosis. MS patients had osteoporosis more frequently than HA/HSP patients, though the difference was not significant after adjusting for confounders. Osteoporosis and bone health should be considered in all patients with both inflammatory and degenerative chronic neurological diseases.

• Koht, Jeanette; Løstegaard, Sven Olav; Wedding, Iselin Marie; Vidailhet, Marie; Louha, Malek & Tallaksen, Chantal (2016). Benign hereditary chorea, not only chorea: a family case presentation. Cerebellum & ataxias. 3. doi: 10.1186/s40673-016-0041-7. Full text in Research Archive Show summary

  Background Benign hereditary chorea is a rare disorder which is characterized by early onset, non-progressive choreic movement disturbance, with other hyperkinetic movements and unsteadiness also commonly seen. Hypothyroidism and lung disease are frequent additional features. The disorder is caused by mutations of the NKX2-1 gene on chromosome 14. Case presentation A Norwegian four-generation family with eight affected was identified. All family members had an early onset movement disorder, starting before one year of age with motor delay and chorea. Learning difficulties were commonly reported from early school years. The family presented with choreic movements at rest, but other movements were seen; myoclonus, dystonia, ataxia, stuttering and tics-like movements. All patients reported unsteadiness and ataxic gait was observed in two patients. Videos are provided in the supplementary material. Most affected family members had asthma and a subclinical or clinical hypothyroidism. Sequencing revealed a mutation in the NKX2-1 gene in all eight affected family members. Conclusions This is the first Norwegian family with benign hereditary chorea due to a mutation in the NKX2-1 gene, c.671 T > G (p.Leu224Arg). This family demonstrates well the wide phenotype, including dystonia, myoclonus and ataxia.

• Stergiou, Christos; Lazaridis, Konstantinos; Zouvelou, Vasiliki; Tzartos, John; Mantegazza, Renato & Antozzi, Carlo [Show all 39 contributors for this article] (2016). Titin antibodies in "seronegative" myasthenia gravis - A new role for an old antigen. Journal of Neuroimmunology. ISSN 0165-5728. 292, p. 108–115. doi: 10.1016/j.jneuroim.2016.01.018. Full text in Research Archive
• Rydning, Siri Lynne; Wedding, Iselin Marie; Koht, Jeanette; Chawla, Maninder Singh; Øye, Ane-Marte & Sheng, Ying [Show all 9 contributors for this article] (2016). A founder mutation p.H701P identified as a major cause of SPG7 in Norway. European Journal of Neurology. ISSN 1351-5101. 23(4), p. 763–771. doi: 10.1111/ene.12937. Full text in Research Archive Show summary

  Background and purpose: SPG7 is one of the most common forms of autosomal recessive hereditary spastic paraplegia. The phenotype has been shown to be heterogeneous, varying from a complex spastic ataxia to pure spastic paraplegia or pure ataxia. The aim of this study was to clinically and genetically characterize patients with SPG7 in Norway. Methods: Six Norwegian families with a clinical diagnosis of hereditary spastic paraplegia were diagnosed with SPG7 through Sanger sequencing and whole-exome sequencing. Haplotypes were established to identify a possible founder mutation. All patients were thoroughly examined and the clinical and molecular findings are described. Results: The core phenotype was spastic paraparesis with ataxia, bladder disturbances and progressive external ophthalmoplegia. The variant p.H701P was identified in homozygous state in one family and in compound heterozygous state in three families. Haplotype analysis of seven surrounding single nucleotide polymorphisms supports that this variant resides on a founder haplotype. Four of the families were compound heterozygous for the previously well-described p.A510V variant. Conclusion: SPG7 is a common subgroup of hereditary spinocerebellar disorders in Norway. The broad phenotype in the Norwegian SPG7 population illustrates the challenges with the traditional dichotomous classification of hereditary spinocerebellar disorders into hereditary spastic paraplegia or hereditary ataxia. A Norwegian founder mutation p.H701P was identified in four out of six families, making it a major cause of SPG7 in Norway.

• Wedding, Iselin Marie; Kroken, Mette; Henriksen, Sandra Pilar; Selmer, Kaja Kristine; Fiskerstrand, Torunn & Knappskog, Per [Show all 8 contributors for this article] (2015). Friedreich ataxia in Norway - An epidemiological, molecular and clinical study. Orphanet Journal of Rare Diseases. 10(1), p. 1–17. doi: 10.1186/s13023-015-0328-4. Full text in Research Archive Show summary

  BACKGROUND: Friedreich ataxia is an autosomal recessive hereditary spinocerebellar disorder, characterized by progressive limb and gait ataxia due to proprioceptive loss, often complicated by cardiomyopathy, diabetes and skeletal deformities. Friedreich ataxia is the most common hereditary ataxia, with a reported prevalence of 1:20 000 - 1:50 000 in Central Europe. Previous reports from south Norway have found a prevalence varying from 1:100 000 - 1:1 350 000; no studies are previously done in the rest of the country. METHODS: In this cross-sectional study, Friedreich ataxia patients were identified through colleagues in neurological, pediatric and genetic departments, hospital archives searches, patients' associations, and National Centre for Rare Disorders. All included patients, carriers and controls were investigated clinically and molecularly with genotype characterization including size determination of GAA repeat expansions and frataxin measurements. 1376 healthy blood donors were tested for GAA repeat expansion for carrier frequency analysis. RESULTS: Twenty-nine Friedreich ataxia patients were identified in Norway, of which 23 were ethnic Norwegian, corresponding to a prevalence of 1:176 000 and 1:191 000, respectively. The highest prevalence was seen in the north. Carrier frequency of 1:196 (95 % CI = [1:752-1:112]) was found. Homozygous GAA repeat expansions in the FXN gene were found in 27/29, while two patients were compound heterozygous with c.467 T < C, L157P and the deletion (g.120032_122808del) including exon 5a. Two additional patients were heterozygous for GAA repeat expansions only. Significant differences in the level of frataxin were found between the included patients (N = 27), carriers (N = 37) and controls (N = 27). CONCLUSIONS: In this first thorough study of a complete national cohort of Friedreich ataxia patients, and first nation-wide study of Friedreich ataxia in Norway, the prevalence of Friedreich ataxia in Norway is lower than in Central Europe, but higher than in the last Norwegian report, and as expected from migration studies. A south-north prevalence gradient is present. Based on Hardy Weinberg's equilibrium, the carrier frequency of 1:196 is consistent with the observed prevalence. All genotypes, and typical and atypical phenotypes were present in the Norwegian population. The patients were phenotypically similar to European cohorts. Frataxin was useful in the diagnostic work-up of heterozygous symptomatic cases.

• Monin, Marie-Lorraine; Montcel, Sophie Tezenas du; Marelli, Cecilia; Cazeneuve, Cecile; Charles, Perrine & Tallaksen, Chantal Marie Elisabeth [Show all 10 contributors for this article] (2015). Survival and severity in dominant cerebellar ataxias. Annals of clinical and translational neurology. 2(2), p. 202–207. doi: 10.1002/acn3.156. Full text in Research Archive
• Coutelier, Marie; Goizet, Cyril; Durr, Alexandra; Habarou, Florence; Morais, Sara & Dionne-Laporte, Alexandre [Show all 34 contributors for this article] (2015). Alteration of ornithine metabolism leads to dominant and recessive hereditary spastic paraplegia. Brain. ISSN 0006-8950. 138(8), p. 2191–2205. doi: 10.1093/brain/awv143. Full text in Research Archive
• Boldingh, Marion Ingeborg; Dekker, Luuk; Maniaol, Angelina; Brunborg, Cathrine; Lipka, Alexander F. & Niks, Erik H. [Show all 8 contributors for this article] (2015). An up-date on health-related quality of life in myasthenia gravis -results from population based cohorts. Health and Quality of Life Outcomes. 13:115. doi: 10.1186/s12955-015-0298-1. Full text in Research Archive Show summary

  Abstract Current available therapies control Myasthenia gravis (MG) reasonably well, but Health Related Quality of life (HRQOL) remains lower than expected. The aim was provide insights in how HRQOL in MG stands across borders and time, compare the scores to general population controls and other chronic disorders and assess the impact of potential predictors for quality of life such as a) clinical characteristics b) antibodies c) thymoma and d) treatment in a population-based cohort. Methods We designed a population-based cross-sectional study including 858 patients, 373 from Norway and 485 from the Netherlands. The Short Form Health Survey 36 (SF-36) and a cross-cultural validated questionnaire were used. Data were in addition compared to the general population, other chronic diseases and previous studies. Results Mean physical composite score was 59.4 and mental composite score 69.0 with no differences between the countries. The mean HRQOL score was lower in patients with bulbar and generalized symptoms (p < 0.001) compared to sex and age adjusted healthy controls, but not in patients with ocular symptoms or patients in remission. Multivariate analysis revealed that female gender, generalized symptoms and use of secondary immunosuppressive drugs at the time of testing were risk factors for reduced HRQOL. Conclusions Remission and absence of generalized symptoms were favorable factors for HRQOL in MG patients. Historically, the HRQOL levels have not changed since 2001 and no new clinical predictors could be detected in this exhaustive population-based study. Further studies should explore the impact of non clinical factors like ethnic variations, socio-economic and hormonal factors on HRQOL.

• Boldingh, Marion Ingeborg; Maniaol, Angelina; Brunborg, Cathrine; Dekker, Luuk; Heldal, Anne Taraldsen & Lipka, Alexander F. [Show all 10 contributors for this article] (2015). Geographical distribution of myasthenia gravis in Northern Europe - Results from a population-based study from two countries. Neuroepidemiology. ISSN 0251-5350. 44(4), p. 221–231. doi: 10.1159/000431036. Full text in Research Archive
• Tsonis, Anastasios I.; Zisimopoulou, Paraskevi; Lazaridis, Konstantinos N.; Tzartos, John; Matsigkou, Eirini & Zouvelou, Vasiliki [Show all 37 contributors for this article] (2015). MuSK autoantibodies in myasthenia gravis detected by cell based assay - A multinational study. Journal of Neuroimmunology. ISSN 0165-5728. 284, p. 10–17. doi: 10.1016/j.jneuroim.2015.04.015. Full text in Research Archive
• Avidan, Nili; Panse, Rozen Le; Harbo, Hanne Flinstad; Bernasconi, Pia; Poulas, Konstantinos & Ginzburg, Elizabeta [Show all 28 contributors for this article] (2014). VAV1 and BAFF, via NFκB pathway, are genetic risk factors for myasthenia gravis. Annals of clinical and translational neurology. 1(5), p. 329–339. doi: 10.1002/acn3.51. Full text in Research Archive
• Wedding, Iselin Marie; Koht, Jeanette; Tran, Gia Tuong Thi; Misceo, Doriana; Selmer, Kaja Kristine & Holmgren, Asbjørn [Show all 10 contributors for this article] (2014). Spastic paraplegia type 7 is associated with multiple mitochondrial DNA deletions. PLOS ONE. 9(1). doi: 10.1371/journal.pone.0086340. Full text in Research Archive Show summary

  Spastic paraplegia 7 is an autosomal recessive disorder caused by mutations in the gene encoding paraplegin, a protein located at the inner mitochondrial membrane and involved in the processing of other mitochondrial proteins. The mechanism whereby paraplegin mutations cause disease is unknown. We studied two female and two male adult patients from two Norwegian families with a combination of progressive external ophthalmoplegia and spastic paraplegia. Sequencing of SPG7 revealed a novel missense mutation, c.2102A>C, p.H 701P, which was homozygous in one family and compound heterozygous in trans with a known pathogenic mutation c.1454_1462del in the other. Muscle was examined from an additional, unrelated adult female patient with a similar phenotype caused by a homozygous c.1047insC mutation in SPG7. Immunohistochemical studies in skeletal muscle showed mosaic deficiency predominantly affecting respiratory complex I, but also complexes III and IV. Molecular studies in single, microdissected fibres showed multiple mitochondrial DNA deletions segregating at high levels (38–97%) in respiratory deficient fibres. Our findings demonstrate for the first time that paraplegin mutations cause accumulation of mitochondrial DNA damage and multiple respiratory chain deficiencies. While paraplegin is not known to be directly associated with the mitochondrial nucleoid, it is known to process other mitochondrial proteins and it is possible therefore that paraplegin mutations lead to mitochondrial DNA deletions by impairing proteins involved in the homeostasis of the mitochondrial genome. These studies increase our understanding of the molecular pathogenesis of SPG7 mutations and suggest that SPG7 testing should be included in the diagnostic workup of autosomal recessive, progressive external ophthalmoplegia, especially if spasticity is present.

• Koht, Jeanette; Rengmark, Aina Sylvia Haugen; Opladen, Thomas; Bjørnarå, Kari Anne; Selberg, Tore & Tallaksen, Chantal [Show all 8 contributors for this article] (2014). Clinical and genetic studies in a family with a novel mutation in the sepiapterin reductase gene. Acta Neurologica Scandinavica. ISSN 0001-6314. 129(198), p. 7–12. doi: 10.1111/ane.12230. Full text in Research Archive
• Zisimopoulou, P.; Evangelakou, P.; Tzartos, J.; Lazaridis, K.; Zouvelou, V. & Mantegazza, Renato [Show all 32 contributors for this article] (2014). A comprehensive analysis of the epidemiology and clinical characteristics of anti-LRP4 in myasthenia gravis. Journal of Autoimmunity. ISSN 0896-8411. 52, p. 139–145. doi: 10.1016/j.jaut.2013.12.004. Full text in Research Archive
• Heimdal, Ketil Riddervold; Guixe, Monica Sanchez; Aukrust, Ingvild; Bollerslev, Jens; Bruland, Ove & Jablonski, Greg [Show all 17 contributors for this article] (2014). STUB1 mutations in autosomal recessive ataxias - evidence for mutation-specific clinical heterogeneity. Orphanet Journal of Rare Diseases. 9:146. doi: 10.1186/s13023-014-0146-0. Full text in Research Archive Show summary

  Background: A subset of hereditary cerebellar ataxias is inherited as autosomal recessive traits (ARCAs). Classification of recessive ataxias due to phenotypic differences in the cerebellum and cerebellar structures is constantly evolving due to new identified disease genes. Recently, reports have linked mutations in genes involved in ubiquitination (RNF216, OTUD4, STUB1) to ARCA with hypogonadism. Methods and results: With a combination of homozygozity mapping and exome sequencing, we identified three mutations in STUB1 in two families with ARCA and cognitive impairment; a homozygous missense variant (c.194A > G, p.Asn65Ser) that segregated in three affected siblings, and a missense change (c.82G > A, p.Glu28Lys) which was inherited in trans with a nonsense mutation (c.430A > T, p.Lys144Ter) in another patient. STUB1 encodes CHIP (C-terminus of Heat shock protein 70 – Interacting Protein), a dual function protein with a role in ubiquitination as a co-chaperone with heat shock proteins, and as an E3 ligase. We show that the p.Asn65Ser substitution impairs CHIP’s ability to ubiquitinate HSC70 in vitro, despite being able to self-ubiquitinate. These results are consistent with previous studies highlighting this as a critical residue for the interaction between CHIP and its co-chaperones. Furthermore, we show that the levels of CHIP are strongly reduced in vivo in patients’ fibroblasts compared to controls. Conclusions: These results suggest that STUB1 mutations might cause disease by impacting not only the E3 ligase function, but also its protein interaction properties and protein amount. Whether the clinical heterogeneity seen in STUB1 ARCA can be related to the location of the mutations remains to be understood, but interestingly, all siblings with the p.Asn65Ser substitution showed a marked appearance of accelerated aging not previously described in STUB1 related ARCA, none display hormonal aberrations/clinical hypogonadism while some affected family members had diabetes, alopecia, uveitis and ulcerative colitis, further refining the spectrum of STUB1 related disease.

• Horn, Morten Andreas; Nilsen, Kristian Bernhard; Jørum, Ellen; Mellgren, Svein Ivar & Tallaksen, Chantal (2014). Small nerve fiber involvement is frequent in X-linked adrenoleukodystrophy. Neurology. ISSN 0028-3878. 82(19), p. 1678–1683. doi: 10.1212/WNL.0000000000000415. Full text in Research Archive
• Maniaol, Angelina; Boldingh, Marion Ingeborg; Brunborg, Cathrine; Harbo, Hanne Flinstad & Tallaksen, Chantal (2013). Smoking and socio-economic status may affect myasthenia gravis. European Journal of Neurology. ISSN 1351-5101. 20(3), p. 453–460. doi: 10.1111/j.1468-1331.2012.03843.x. Full text in Research Archive
• Horn, Morten Andreas; Erichsen, Martina Moter; Wolff, Anette Susanne Bøe; Månsson, Jan-Eric; Husebye, Eystein Sverre & Tallaksen, Chantal [Show all 7 contributors for this article] (2013). Screening for X-linked adrenoleukodystrophy among adult men with Addison's disease. Clinical Endocrinology. ISSN 0300-0664. 79(3), p. 316–320. doi: 10.1111/cen.12159. Full text in Research Archive
• Horn, Morten Andreas; Retterstøl, Lars; Abdelnoor, Michael; Skjeldal, Ola & Tallaksen, Chantal (2013). Adrenoleukodystrophy in Norway: High Rate of De Novo Mutations and Age-Dependent Penetrance. Pediatric Neurology. ISSN 0887-8994. 48(3), p. 212–219. doi: 10.1016/j.pediatrneurol.2012.12.007. Full text in Research Archive
• Sumathipala, Dulika S.; Abeysekera, Gayan S.; Jayasekara, Rohan W.; Tallaksen, Chantal & Dissanayake, Vajira H.W (2013). Autosomal dominant hereditary ataxia in Sri Lanka. BMC Neurology. 13. doi: 10.1186/1471-2377-13-39. Full text in Research Archive Show summary

  Background Spinocerebellar ataxias (SCA) are a group of hereditary neurodegenerative disorders. Prevalence of SCA subtypes differ worldwide. Autosomal dominant ataxias are the commonest types of inherited ataxias seen in Sri Lanka. The aim of the study is to determine the genetic etiology of patients with autosomal dominant ataxia in Sri Lanka and to describe the clinical features of each genetic subtype. Methods Thirty four patients with autosomal dominant ataxia were recruited. For every patient the following was done: recording of clinical details and genotyping for SCA 1, 2, 3, 6, 7, 8, 12, and 17. Results Sixty one per cent of the subjects were identified as SCA1. One subject had SCA2, 12 remain unidentified. Mean age at onset was 34.8 ± 10years for SCA1 and 32.7 ± 9.8 for non SCA1. 76% of SCA1 patients and 50% of non SCA1 were using walking aids. Quantification of symptoms and signs were similar in the SCA1 and non SCA1 groups. Clinical depression was evidenced in 68.4% of SCA1 and 75% non SCA-1 patients. Mean CAG repeat length in SCA1 patients was 52.0 ± 3.8, with greater anticipation seen with paternal inheritance. Conclusion SCA1 was the predominant subtype and showed similar phenotype to previous reports. However, disease severity was higher and depression more prevalent in this population than previously described.

• Wedding, Iselin Marie; Koht, Jeanette; Dietrichs, Espen; Landrø, Nils Inge & Tallaksen, Chantal (2013). Cognition is only minimally impaired in Spinocerebellar ataxia type 14 (SCA14): a neuropsychological study of ten Norwegian subjects compared to intrafamilial controls and population norm. BMC Neurology. 13:186. doi: 10.1186/1471-2377-13-186. Full text in Research Archive Show summary

  Background: There is an increasing awareness of the role of the cerebellum not only in motor, but also in cognitive and emotional functions. Spinocerebellar ataxia type 14 (SCA14) is an autosomal dominant hereditary ataxia characterized by a relatively pure cerebellar phenotype. Cognitive impairment has been reported in studies with phenotype descriptions of SCA14, but previous studies have been small without control groups, and no homogeneous and systematic test panel has been used. The objective of this study was to thoroughly characterize the neuropsychological profile in ten Norwegian SCA14 subjects compared to unaffected family members and population norm data. Methods: Ten SCA14 subjects and ten intrafamilial unaffected age- and education-matched controls from two Norwegian families were included. The unaffected intrafamilial controls included six first degree relatives, two second degree relatives, and two spouses. General intellectual ability, memory, visuoperceptive skills, psychomotor speed, executive functions, depression and anxiety were examined using internationally standardized tests, with minimal need for manual response to avoid motor bias. Results: No significant cognitive deficit was found in SCA14 subjects compared to intrafamilial controls. Verbal IQ, verbal executive function and psychomotor speed tended to be reduced in affected subjects, but previously reported non-verbal executive dysfunction was not confirmed in this study. Conclusion: Only subtle cognitive impairment was found in SCA14 affected subjects. The current findings do not confirm earlier reports of cognitive dysfunction in SCA14, but does shows a mild impairment in specific verbal executive functions. Genotypic differences may partly account for this discrepancy, and further studies on larger materials are needed to verify the findings.

• Koht, Jeanette; Stevanin, G; Durr, A; Mundwiller, E; Brice, A & Tallaksen, Chantal (2012). SCA14 in Norway, two families with autosomal dominant cerebellar ataxia and a novel mutation in the PRKCG gene. Acta Neurologica Scandinavica. ISSN 0001-6314. 125(2), p. 116–122. doi: 10.1111/j.1600-0404.2011.01504.x. Full text in Research Archive
• Gregersen, Peter K.; Kosoy, Roman; Lee, Annette T.; Lamb, Janine; Sussman, Jon & McKee, David [Show all 29 contributors for this article] (2012). Risk for Myasthenia Gravis Maps to a 151Pro!Ala Change in TNIP1 and to Human Leukocyte Antigen-B*08. Annals of Neurology. ISSN 0364-5134. 72(6), p. 927–935. doi: 10.1002/ana.23691. Full text in Research Archive
• Maniaol, Angelina; Elsais, Ahmed; Lorentzen, Åslaug Rudjord; Owe, Jone Furulund; Viken, Marte K & Sæther, Hanne Skarpodde [Show all 17 contributors for this article] (2012). Late onset myasthenia gravis is associated with HLA DRB1*15:01 in the Norwegian population. PLOS ONE. 7(5). doi: 10.1371/journal.pone.0036603. Full text in Research Archive Show summary

  Background: Acquired myasthenia gravis (MG) is a rare antibody-mediated autoimmune disease caused by impaired neuromuscular transmission, leading to abnormal muscle fatigability. The aetiology is complex, including genetic risk factors of the human leukocyte antigen (HLA) complex and unknown environmental factors. Although associations between the HLA complex and MG are well established, not all involved components of the HLA predisposition to this heterogeneous disease have been revealed. Well-powered and comprehensive HLA analyses of subgroups in MG are warranted, especially in late onset MG. Methodology/Principal Findings: This case-control association study is of a large population-based Norwegian cohort of 369 MG patients and 651 healthy controls. We performed comprehensive genotyping of four classical HLA loci (HLA-A, -B, -C and -DRB1) and showed that the DRB1*15:01 allele conferred the strongest risk in late onset MG (LOMG; onset ≥60years) (OR 2.38, pc7.4×10−5). DRB1*13:01 was found to be a protective allele for both early onset MG (EOMG) and LOMG (OR 0.31, pc 4.71×10−4), a finding not previously described. No significant association was found to the DRB1*07:01 allele (pnc = 0.18) in a subset of nonthymomatous anti-titin antibody positive LOMG as reported by others. HLA-B*08 was mapped to give the strongest contribution to EOMG, supporting previous studies. Conclusion: The results from this study provide important new information concerning the susceptibility of HLA alleles in Caucasian MG, with highlights on DRB1*15:01 as being a major risk allele in LOMG.

• Burgunder, Jean-Marc; Schöls, Ludger; Baets, Jonathan; Andersen, Peter Munch; Gasser, Thomas & Szolnoki, Zoltan [Show all 18 contributors for this article] (2011). EFNS guidelines for the molecular diagnosis of neurogenetic disorders: motoneuron, peripheral nerve and muscle disorders. European Journal of Neurology. ISSN 1351-5101. 18(2), p. 207–E20. doi: 10.1111/j.1468-1331.2010.03069.x. Full text in Research Archive
• Alseth, Espen Homleid; Maniaol, Angelina; Elsais, Ahmed; Nakkestad, Hanne Linda; Tallaksen, Chantal & Gilhus, Nils Erik [Show all 7 contributors for this article] (2011). Investigation for RAPSN and DOK-7 mutations in a cohort of seronegative myasthenia gravis patients. Muscle and Nerve. ISSN 0148-639X. 43(4), p. 574–577. doi: 10.1002/mus.21919. Full text in Research Archive
• Holmøy, Trygve; Braaten, Øivind; Hynås, Inger Anette & Tallaksen, Chantal (2011). En ung kvinne som mistet kraften i ett bein. Tidsskrift for Den norske legeforening (Tidsskriftet). ISSN 0029-2001. 6, p. 583–586. doi: 10.4045/tidsskr.09.1499. Full text in Research Archive
• Yu-Wai-Man, Patrick; Griffiths, Philip G.; Gorman, Grainne S.; Lourenco, Charles Marques; Wright, Alan F. & Auer-Grumbach, Michaela [Show all 36 contributors for this article] (2010). Multi-system neurological disease is common in patients with OPA1 mutations. Brain. ISSN 0006-8950. 133, p. 771–786. doi: 10.1093/brain/awq007. Full text in Research Archive
• Schlipf, NA; Beetz, C; Schule, R; Stevanin, G; ERICHSEN, ANNE KJERSTI & Forlani, S [Show all 17 contributors for this article] (2010). A total of 220 patients with autosomal dominant spastic paraplegia do not display mutations in the SLC33A1 gene (SPG42). European Journal of Human Genetics. ISSN 1018-4813. 18(9), p. 1065–1067. doi: 10.1038/ejhg.2010.68. Full text in Research Archive
• Burgunder, JM; al, More authors Et; Tallaksen, Chantal & Harbo, Hanne Flinstad (2010). EFNS guidelines for the molecular diagnosis of neurodegenerative disorders:motoneuron, peripheral nerve and muscle disorders. European Journal of Neurology. ISSN 1351-5101. 18, p. 207–217. doi: 10.1111/j.468-1331.2010.03069.x. Full text in Research Archive
• Gasser, T; Finsterer, Josef; Baets, J; Broeckhoven, C Van; Donato, S Di & Fontaine, B [Show all 18 contributors for this article] (2010). EFNS guidelines on the molecular diagnosis of ataxias and spastic paraplegias. European Journal of Neurology. ISSN 1351-5101. 17(2), p. 179–188. doi: 10.1111/j.1468-1331.2009.02873.x. Full text in Research Archive
• Maniaol, Angelina; Brunborg, Cathrine & Tallaksen, Chantal (2010). Development and Validation of a Self-Administered Questionnaire for Myasthenia Gravis Patients. Neuroepidemiology. ISSN 0251-5350. 34(4), p. 253–261. doi: 10.1159/000297753. Full text in Research Archive
• Koht, Jeanette; Tallaksen, Chantal & ERICHSEN, ANNE KJERSTI (2010). Kapitell om ataksier og spastiske parapareser. In Gjerstad, Leif; Helseth, Eirik & Rootwelt, Terje (Ed.), Nevrologi og nevrokirurgi. Fra barn til voksen. 5.utgave. Forlaget Vett & Viten AS. ISSN 9788241206863. Full text in Research Archive
• Burgunder, J-M.; Finsterer, J.; Szolnoki, Z.; Fontaine, B.; Baets, J. & Broeckhoven, C. Van [Show all 17 contributors for this article] (2010). EFNS guidelines on the molecular diagnosis of channelopathies, epilepsies, migraine, stroke, and dementias. European Journal of Neurology. ISSN 1351-5101. 17(5), p. 641–648. doi: 10.1111/j.1468-1331.2010.02985.x. Full text in Research Archive
• Vevelstad, Merete Synnøve; Pettersen, S; Tallaksen, C & Brørs, Odd (2009). O-demethylation of codeine to morphine inhibited by low-dose levomepromazine. European Journal of Clinical Pharmacology. ISSN 0031-6970. 65(8), p. 795–801. doi: 10.1007/s00228-009-0640-9. Full text in Research Archive
• ERICHSEN, ANNE KJERSTI; Server, A.; Landrø, Nils Inge; Sandvik, L & Tallaksen, Chantal (2009). Proton magnetic resonance spectroscopy and cognition in patients with spastin mutations. Journal of the Neurological Sciences. ISSN 0022-510X. 277(1-2), p. 124–129. doi: 10.1016/j.jns.2008.10.030. Full text in Research Archive
• ERICHSEN, ANNE KJERSTI; Koht, Jeanette; Stray-Pedersen, Asbjørg; Abdelnoor, Michael & Tallaksen, Chantal (2009). Prevalence of hereditary ataxia and spastic paraplegia in southeast Norway: a population-based study. Brain. ISSN 0006-8950. 132, p. 1577–1588. doi: 10.1093/brain/awp056. Full text in Research Archive
• Selmer, Kaja K.; Eriksson, AS; Brandal, K; Egeland, Thore; Tallaksen, C & Undlien, DE (2009). Parental SCN1A mutation mosaicism in familial Dravet syndrome. Clinical Genetics. ISSN 0009-9163. 76(4), p. 398–403. doi: 10.1111/j.1399-0004.2009.01208.x. Full text in Research Archive
• Koht, Jeanette Aimee; Bjornara, KA; Jørum, Ellen & Tallaksen, Chantal (2009). Ataxia with vitamin E deficiency in southeast Norway, case report. Acta Neurologica Scandinavica. ISSN 0001-6314. 120, p. 42–45. Full text in Research Archive
• Erichsen, AK; Stevanin, G; Denora, P; Brice, A & Tallaksen, Chantal (2008). SPG11 - the most common type of recessive spastic paraplegia in Norway? Acta Neurologica Scandinavica. ISSN 0001-6314. 117, p. 46–50. Full text in Research Archive
• Tallaksen, Chantal (2008). Arvelige ataksier. Tidsskrift for Den norske legeforening (Tidsskriftet). ISSN 0029-2001. 128(17), p. 1977–1980. Full text in Research Archive
• Horn, Morten Andreas; Brink, D. M. van den; Wanders, R.J.A.; Duran, Marinus; Poll-The, B. T. & Tallaksen, Chantal [Show all 9 contributors for this article] (2007). Phenotype of adult Refsum disease due to a defect in peroxin 7. Neurology. ISSN 0028-3878. 68, p. 698–700. doi: 10.1212/01.wnl.0000257903.51937.88. Full text in Research Archive Show summary

  The biochemical hallmark of adult Refsum disease (ARD) is an isolated deficiency in the breakdown of phytanic acid. This usually results from a PHYH gene defect, although some cases have been found to carry a PEX7 defect. We describe the phenotype of such a patient, indistinguishable from that of classic ARD. Hence, we propose the subdivision of ARD into type 1 and type 2, depending on which gene is defective

• Erichsen, AK; Inderhaug, E; Mattingsdal, M; Eiklid, K & Tallaksen, Chantal (2007). Seven novel mutations and four exon deletions in a collection of Norwegian patients with SPG4 hereditary spastic paraplegia. European Journal of Neurology. ISSN 1351-5101. 14, p. 809–814. doi: 10.1111/j.1468-1331.2007.01861.x. Full text in Research Archive
• Koht, Jeanette Aimee & Tallaksen, Chantal (2007). Cerebellar ataxia in the eastern and southern parts of Norway. Acta Neurologica Scandinavica. ISSN 0001-6314. 115. Full text in Research Archive
• Depienne, C; Tallaksen, Chantal; Lephav, JY; Bricka, B; Poea-Guvon, S & Fontaine, B [Show all 9 contributors for this article] (2005). Spastin mutations are frequent in sporadic spastic paraparesis and their spectrum is different from the one observed in familial cases. Journal of Medical Genetics. ISSN 0022-2593. Full text in Research Archive
• Dietrichs, Espen & Tallaksen, Chantal (2004). Genetikk ved bevegelsesforstyrrelser - dystoni, tremor og chorea. Tidsskrift for Den norske legeforening (Tidsskriftet). ISSN 0029-2001. p. 2236-2237–2236-2237. Full text in Research Archive
• Dürr, A; Camuzat, A; Colin, E; Tallaksen, Chantal; Hannequin, D & Couthino, P [Show all 13 contributors for this article] (2004). Atlastin mutations are frequent in young onset autosomal dominant spastic paralegia. Archives of Neurology. ISSN 0003-9942. 61, p. 1867–1873. Full text in Research Archive
• Tallaksen, Chantal; Guichart-Gomez, E; Verpillat, P; Hahn-Barma, V; Ruberg, M & Fontaine, B [Show all 9 contributors for this article] (2004). Subtle, cognitive impairment but no dementia in patients with spastims mutations. Archives of Neurology. ISSN 0003-9942. 60, p. 1113–1118. Full text in Research Archive
• Tallaksen, Chantal; Skjeldal, OH & Gjerstad, L (2004). Spinocecerebellare degenerasjoner. In Nevrologi og Nevrokirurgi, Vett & Viten AS. p. 423–430. Full text in Research Archive
• Dürr, A & Tallaksen, Chantal (2004). SPG4 Hereditary Spastic Paraplegia. Gene Reviews : Gene Tests. Full text in Research Archive
• Tallaksen, Chantal; Guichart-Gomez, E; Verpillat, P; Hahn-Barma, V; Ruberg, M & Fontaine, B [Show all 9 contributors for this article] (2004). Subtle cognitive inpairment but no dementia in patients with spastin mutations. Archives of Neurology. ISSN 0003-9942. 60, p. 1113–1118. Full text in Research Archive
• Tallaksen, Chantal & Dietrichs, Espen (2004). Genetikk ved bevegelsesforstyrrelser- spinocerebellære lidelser. Tidsskrift for Den norske legeforening (Tidsskriftet). ISSN 0029-2001. 17(124), p. 2233–2235. Full text in Research Archive
• Tallaksen, Chantal (2003). Subtle cognitive impairment but no dementia in patients with spastin mutations. Archives of Neurology. ISSN 0003-9942. 60, p. 1113–1118. Full text in Research Archive
• Tallaksen, Chantal; Sande, Sverre Arne; Bøhmer, Thomas; Bell, Helge & Karlsen, Jan (1993). Kinetics of thiamin phosphate esters in human blood, plasma and urine after 50 mg intravenously or orally. European Journal of Clinical Pharmacology. ISSN 0031-6970. 44, p. 73–78. Full text in Research Archive

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• Roux, Thomas; Barbier, Mathieu; Papin, Mélanie; Davoine, Claire-Sophie; Sayah, Sabrina & Coarelli, Giulia [Show all 95 contributors for this article] (2021). Correction: Clinical, neuropathological, and genetic characterization of STUB1 variants in cerebellar ataxias: a frequent cause of predominant cognitive impairment (Genetics in Medicine, (2020), 22, 11, (1851-1862), 10.1038/s41436-020-0899-x). Genetics in Medicine. ISSN 1098-3600. 23(10), p. 2021–2021. doi: 10.1038/s41436-020-01064-y. Full text in Research Archive
• Arntzen, Kjell Arne; Høyer, Helle; Ørstavik, Kristin; Tallaksen, Chantal; Vedeler, Christian A. & Østern, Rune André Helland [Show all 9 contributors for this article] (2018). Clinical characteristics, minimum prevalence and spectrum of SH3TC2 mutations in Norway. Full text in Research Archive
• Rydning, Siri Lynne; Backe, Paul Hoff; Sousa, Mirta; Iqbal, Zafar; Øye, Ane-Marte & Sheng, Ying [Show all 14 contributors for this article] (2017). Corrigendum: Novel UCHL1 mutations reveal new insights into ubiquitin processing. Human Molecular Genetics. ISSN 0964-6906. 26(6), p. 1217–1218. doi: 10.1093/hmg/ddx072. Full text in Research Archive
• Hikmat, Omar; Tzoulis, Charalampos; Klingenberg, Claus; Rasmussen, Magnhild; Tallaksen, Chantal & Brodtkorb, Eylert [Show all 10 contributors for this article] (2017). Erratum to: The presence of anaemia negatively influences survival in patients with POLG disease (Journal of Inherited Metabolic Disease, (2017), 40, 6, (861-866), 10.1007/s10545-017-0084-9). The Journal of Inherited Metabolic Disease (JIMD). ISSN 0141-8955. 41(1), p. 153–153. doi: 10.1007/s10545-017-0092-9. Full text in Research Archive
• Tallaksen, Chantal & Müller, Ulrich (2017). Cancer and neurodegeneration: Time to move beyond Janus? Neurology. ISSN 0028-3878. 88(12), p. 1106–1107. doi: 10.1212/WNL.0000000000003727. Full text in Research Archive
• Arntzen, Kjell Arne; Høyer, Helle; Ingebrigtsen, Monica; Busk, Øyvind Løvold; Holla, Øystein Lunde & Tveten, Kristian [Show all 13 contributors for this article] (2016). Prevalence and spectrum of SH3TC2 mutations in Norway. Full text in Research Archive
• Horn, Morten Andreas; Retterstøl, Lars; Abdelnoor, Michael; Skjeldal, Ola & Tallaksen, Chantal (2015). Age-dependent penetrance among females with X-linked adrenoleukodystrophy. Brain. ISSN 0006-8950. 138(1), p. e325–e325. doi: 10.1093/brain/awu232. Full text in Research Archive
• Wedding, Iselin Marie; Koht, Jeanette; Landro, N. I. & Tallaksen, Chantal (2012). Cerebellum - more than motor control? Cognition in spinocerebellar ataxia type 14. European Journal of Neurology. ISSN 1351-5101. 19, p. 62–62. Full text in Research Archive
• Montcel, Sophie Tezenas Du; Charles, Perrine; Goizet, Cyril; Marelli, Cecilia; Anheim, Mathieu & Guyant-Marchal, Lucie [Show all 16 contributors for this article] (2012). Sample Size Estimation for Future Therapeutic Trials in SCAs. Neurology. ISSN 0028-3878. 78. Full text in Research Archive
• Maniaol, Angelina; Boldingh, Marion Ingeborg; Brunborg, Cathrine; Harbo, Hanne Flinstad & Tallaksen, Chantal (2011). A POPULATION-BASED DESCRIPTIVE EPIDEMIOLOGIC STUDY OF MYASTHENIA GRAVIS IN NORWAY. European Journal of Neurology. ISSN 1351-5101. 18(S2), p. 276–276. Full text in Research Archive
• Tallaksen, Chantal & Coutinho, P (2010). Clinical diagnosis of hereditary spastic paraplegia. European Journal of Neurology. ISSN 1351-5101. 17(supp. 3), p. 642–642. Full text in Research Archive
• Tallaksen, Chantal & Reid, E. (2010). Molecular genetics of spastic paraplegia. European Journal of Neurology. ISSN 1351-5101. 17, p. 641–641. Full text in Research Archive
• Koht, Jeanette & Tallaksen, Chantal (2010). Two new autosomal dominant ataxia loci. Full text in Research Archive
• ERICHSEN, ANNE KJERSTI; Koht, Jeanette Aimee; Abdelnoor, M & Tallaksen, Chantal (2008). Hereditary spastic paraplegia in south-eastern Norway. European Journal of Neurology. ISSN 1351-5101. 15, p. 354–354. Full text in Research Archive

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