Spinocerebellar ataxia type 2 in a Turkish family.

Autosomal dominant spinocerebellar ataxias are neurodegenerative disorders that generally present in adulthood. Due to extreme expansion of the repeat size during spermatogenesis, they can also be observed in childhood. The diagnosis in childhood is very difficult in the absence of family history. Here we describe an 8-year-old girl with spinocerebellar ataxia type 2 who presented with progressive ataxia, cognitive deficits, and dysarthria. A detailed family history exhibited similarly affected cases on the paternal side. Molecular testing for spinocerebellar ataxia type 2 revealed abnormal "cytosineadenine-guanosine" expansion in all affected family members. The number of cytosine-adenine-guanosine repeats in the index case was 70. The mean size of expansion in the relatives of the patient was 42 (39-46). This finding explains the early onset of symptoms in the index case.