Molecular re-investigation of patients with Huntington's disease in Wessex reveals a family with dentatorubral and pallidoluysian atrophy.

Dentatorubral and pallidolysian atrophy (DRPLA), a neurological disorder thought to be rare in European populations, is caused by a triplet repeat expansion in the B37 gene on chromosome 12. This disorder can phenotypically mimic Huntington's disease (HD) which is also caused by a repeat expansion. We have analysed 139 affected individuals for the HD triplet repeat expansion and found 132 patients had one normal and one expanded allele. Two patients had an expansion on both chromosomes and five patients had two normal-size alleles. Of these five patients, two were considered to be atypical Two patients who were father and daughter were found to have an expansion of the DRPLA triplet repeat. This therefore constitutes the second such family described in the United Kingdom.