Spinocerebellar ataxia type 38 (SCA38) is an autosomal dominant disease caused by mutations in the ELOVL5 gene. Each affected subjects has a 50% chance to transmit the disease to his/her offspring.
To date, all affected subjects have an affected parent and no instances of de novo ELOVL5 mutations have been reported.
Penetrance seems to be complete and age-dependent: subject carrying the c.689G>T variant p.(Gly230Val) were all symptomatic by the age of 50 yrs. In contrast to other repeat expansion-associated spinocerebellar ataxias SCA38 does not show anticipation.
The disease is probably rare, having been described in four families worldwide (three Italian and one French). A screening performed in 346 Chinese ataxic patients did not reveal any ELOVL5 variant. A fifth family with SCA38 has been reported in literature, but the significance of the variant described is dubious (see the Professionals – Molecular characteristics section).