ITPR1 and spinocerebellar ataxia type 29: <h4>Background</h4>Mutations in the Inositol 1,4,5-Trisphosphate Receptor Type 1 (<i>ITPR1)</i> gene cause spinocerebellar ataxia type 29 (SCA29), a rare congenital-onset autosomal dominant non-progressive cerebellar ataxia.