| A rare subtype of type 1 autosomal dominant cerebellar ataxia with characteristics of cerebellar ataxia, tremor and cognitive impairment. Prevalence is unknown. Fewer than 80 patients affected by the disease have been identified to date. Age of onset is from 20 to 66 years. Genetic testing has shown that patients originally classified under SCA15 and SCA16 have the same subtype caused by a deletion in the inositol 1,4,5-triphosphate receptor 1 ITPR1 gene (3p26.1). Prognosis is generally good and life-shortening events do not usually occur. |
