Spinocerebellar Ataxia Type 19/22

Spinocerebellar ataxia type 19 (SCA19) is a very rare subtype of type I autosomal dominant cerebellar ataxia (ADCA type I; see this term). It is characterized by mild cerebellar ataxia, cognitive impairment, low scores on the Wisconsin Card Sorting Test measuring executive function, myoclonus, and postural tremor.

Epidemiology

Prevalence is unknown. Only 12 cases in a 5-generation Dutch family have been reported to date.

Clinical description

SCA19 presents in the 3rd decade of life with symptomatic disease onset ranging from 10 to 46 years. Onset symptoms of SCA22 (see this term) overlap significantly with those of SCA19 but with a more narrow age range of 35 to 46 years.

Etiology

Linkage to locus 1p21-q21 has been proposed but the gene mutation has not been identified.

Prognosis

Prognosis is good. SCA19 does not impact life expectancy to any major extent, and some patients live to over 80 years of age.