AbstractBackgroundIn Thais, the most prevalent type of spinocerebellar ataxia (SCA) is type 3, most commonly known as Machado–Joseph disease (MJD), followed by SCA type 1 (SCA1), SCA2, and SCA6.ObjectivesTo describe the epidemiological, clinical, and genotypic features of SCA in northeastern Thailand and to study 2 associations: between syndromic features and the genotype of SCA, and between health determinants and scores on the scale for the assessment and rating of ataxia (SARA).MethodsWe conducted a cross-sectional study of 24 patients with autosomal dominant SCA from 13 families recruited from Buriram province in northeast Thailand between December 2009 and January 2014. Patients provided a clinical history and were examined by a neurologist. DNA was extracted from the peripheral blood of each patient. We analyzed associations between the type of SCA and sex, age, family history, clinical features, any underlying disease, age at onset, body weight, smoking status, family history, alcohol consumption, head injury history, and SARA.ResultsSeven of the families were positive for SCA1 and 6 for MJD. There were 24 index patients from these autosomal dominant SCA families, including 13 with SCA1 and 11 with MJD. Their average age was 43.7 years (range 20–72 years), whereas their average age at disease onset was 36.9 years (range 18–59 years). Pyramidal signs between MJD and SCA1 were not significantly different. Extrapyramidal features appeared uncommon. Horizontal nystagmus and upward gaze paresis were significantly associated with MJD. There were no significant differences in demographic data between the groups with SARA scores ≥15 or <15.ConclusionsMJD and SCA1 were the 2 adult-onset cerebellar degenerative diseases found in Buriram province. Clinical clues for differentiating between them were upward gaze paresis and horizontal nystagmus, which were significantly more common in MJD.
Spinocerebellar ataxia type 13 mutation that is associated with disease onset in infancy disrupts axonal pathfinding during neuronal development
