Spinocerebellar ataxia type 6 in relation to CAG repeat length

Objective - The purpose of the present study was to assess the relationship between clinical characteristics of spinocerebellar ataxia type 6 (SCA6) a nd CAG repeat length. Materials and methods - We examined clinical symptoms of 54 patients with SCA6, CAG repeat length was compared among subgroups d ivided by clinical manifestations. Results - The major symptom was progress ive cerebellar ataxia, Truncal or limb ataxia, dysarthria, and nystagmus we re observed in more than 80% of the patients. In analysis of CAG repeat len gth in patients with different types of nystagmus, CAG repeat length was th e longest when both upbeat and downbeat nystagmus existed (P < 0.01). In ad dition, CAG repeat length was longer when the initial symptom was ataxic ga it and was shorter when the initial symptom was dysarthria or ocular sympto m (P < 0.05). Conclusion Clinical features of SCA6 might be influenced by t he length of abnormal CAG repeat.