Topic summary
ATXN1
Extracted from the Wikipedia article Ataxin 1.
Role in disease
ATXN1 is the gene mutated in spinocerebellar ataxia type 1 (SCA1), a dominantly-inherited, fatal genetic disease in which neurons in the cerebellum and brain stem degenerate over the course of years or decades. SCA1 is a trinucleotide repeat disorder caused by expansion of the CAG repeat in ATXN1; this leads to an expanded polyglutamine tract in the protein. This elongation is variable in length, with as few as 6 and as many as 81 repeats reported in humans. Repeats of 39 or more uninterrupted CAG triplets cause disease, and longer repeat tracts are correlated with earlier age of onset and faster progression.