A Spinocerebellar Ataxia Type 6 Patient Caused by De Novo Expansion of Normal Range CAG Repeats

Spinocerebellar ataxia type 6 (SCA6) is classified as a CAG repeat disorder, where the number of expanded CAG repeats often undergoes meiotic instability, when transmitted from one generation to the next. However, in SCA6, both normal and expanded CAG repeats tend to remain stable during transmission due to its relatively small repeat numbers. We herein report de-novo expansion of CAG repeats in SCA6 gene in a 41-year-old female patient, whose parents had normal repeat numbers.