Novel PRKCG/SCA14 mutation in a Dutch spinocerebellar ataxia family: expanding the phenotype.

We report on a family with an autosomal dominant cerebellar ataxia in which we identified a novel mutation in exon 5 of the PRKCG/SCA14 gene that results in a Val138Glu substitution in the encoded protein PKCgamma. While most affected subjects displayed a late-onset uncomplicated form of spinocerebellar ataxia with occasional mild extrapyramidal features (such as postural tremor), one patient presented with a very mild nonprogressive ataxia since the age of 3 years and predominant multifocal myoclonus.