Aprataxin (APTX) gene mutations resembling multiple system atrophy

Mutations of the aprataxin (APTX) gene cause early-onset ataxia with ocular motor apraxia and hypoalbuminemia (EAOH), also called ataxia with oculomotor apraxia type 1. Recent studies showed clinical heterogeneity in patients with EAOH. We describe 2 patients whose clinical features resembled those of multiple system atrophy of the cerebellar subtype (MSA-C) but without ocular motor apraxia and hypoalbuminemia. Each had a different nucleotide transition in the APTX gene (725G→A and 457A→G). These variants on the APTX gene exhibit phenotypic variability.