Heterozygous mutation causes familial ataxia with cognitive affective syndrome (SCA48).

Objective: To describe a new spinocerebellar ataxia (SCA48) characterized by early cerebellar cognitive-affective syndrome (CCAS) and late-onset SCA.

Methods: This is a descriptive study of a family that has been followed for more than a decade with periodic neurologic and neuropsychological examinations, MRI, brain SPECT perfusion, and genetic analysis. Whole exome sequencing was performed in 3 affected and 1 unaffected family member and subsequently validated by linkage analysis of chromosome 16p13.