The OPCA pattern was identified as MSA-C in a few dominant ataxias (SCA1-3, SCA7, SCA34, SCA36, DRPLA), two recessive ataxias (BNS and SCAR7) and the X-linked ataxia associated with the PRPS1 gene mutation. The gene discussed is NOP56; the disease is spinocerebellar ataxia type 1.