[Mutation of the aprataxin gene presenting with Charcot-Marie-Tooth-like neuropathy and cerebellar ataxia].

BACKGROUND

Phenotype-genotype correlations, generally based on predominant associated signs, are being increasingly used to distinguish different types of autosomal recessive cerebellar ataxias (ARCA).

CASE REPORTS: Two brothers developed signs of cerebellar ataxia with peripheral axonal motor and sensory neuropathy, distal muscular atrophy, pes cavus and steppage gait as seen in Charcot-Marie-Tooth neuropathy. The examination also showed oculomotor apraxia. Sural nerve biopsy revealed conspicuous reduction in the density of myelinated fibres but preservation of unmyelinated nerve fibres. Blood tests revealed low serum albumin and elevated cholesterol. A homozygous W279X truncating mutation was identified in exon 6 of the APTX gene, confirming the diagnosis of cerebellar ataxia with oculomotor apraxia type 1 (AOA1).

CONCLUSIONS

These cases illustrate the presentation of AOA1 type of ARCA and discuss the role of peripheral neuropathy in the differential diagnostic of the ARCAs variants.