Spinocerebellar ataxia subtype 40: Report of a case and review of literature

Spinocerebellar ataxias (SCA) are a group of neurodegenerative disorders and are clinically and genetically heterogeneous. Based on the genetic variation, SCAs are grouped into three main categories: i. SCAs caused by expansion of trinucleotides (CAG/polyQ) repeats in the coding region of genes, ii. SCAs caused by repetitive amplification of non-coding regions, and ii. SCAs caused by conventional sequence variants [1]. SCA40 (OMIM # 616053), which is one of the recently described types of autosomal dominant (AD) SCA, belongs to the third category and is caused by heterozygous pathogenic variants in the CCDC88C gene (OMIM * 611204).