Early-Onset Ataxia With Oculomotor Apraxia With a Novel APTX Mutation

Early-onset ataxia with oculomotor apraxia and hypoalbuminemia is an autosomal recessive cerebellar ataxia characterized by oculomotor apraxia, peripheral neuropathy, and hypoalbuminemia. Mutations in aprataxin gene located at chromosome 9q13 have been identified recently in Japanese and European patients. This study reports two cases of siblings with early-onset ataxia with oculomotor apraxia and hypoalbuminemia, which manifested early onset before 2 years of age with relatively rapid progression and severe dystonia. Both of the siblings were compound heterozygotes with aprataxin gene mutations, 689 insT and G692A, in exon 5 that encodes the histidine triad domain of the aprataxin protein. The novel missense mutation, G692A, was not present in 40 unrelated and unaffected individuals.