As previously stated, SCA7 is caused by a highly unstable polymorphic CAG repeat in ATXN7, and the huge variation in CAG repeat length means that the age of onset of the disease is highly variable, occurring from infancy up to 60 years of age where infants have widespread pathogenesis that extends past typical CNS pathology. The gene discussed is ATXN7; the disease is spinocerebellar ataxia 7.