Pseudodominant Friedreich's ataxia with phenotypic heterogeneity

OBJECTIVE: A family with a clinically heterogeneous progressive ataxia in two generations is presented. METHODS: Having eliminated mutations within the known dominant spinocerebellar ataxia genes, the family was investigated for expansion at the Friedreich's gene. RESULTS: The affected members (father, son and daughter) were homozygous for the mutation at the Friedreich's gene, while the unaffected (the mother and her sister) were heterozygous. CONCLUSION: This pseudodominant form of Friedreich's ataxia should be considered in families with an apparently autosomal dominant progressive ataxia in conjunction with sensory neuropathy and pyramidal signs.