HOMOZYGOSITY FOR AN ALLELE CARRYING INTERMEDIATE CAG REPEATS IN THE DENTATORUBRAL-PALLIDOLUYSIAN ATROPHY (DRPLA) GENE RESULTS IN SPASTIC PARAPLEGIA

We report a family with autosomal recessive spastic paraplegia. Patien t 1 was a 37-year-old woman and patient 2 was her 35-year-old sister. They showed spastic paraplegia with mild truncal ataxia and dysarthria but no dementia, epilepsy, myoclonus, or other involuntary movements. They were the products of a consanguineous marriage but the parents w ere neurologically normal. We analyzed the CAG repeats of the dentator ubral-pallidoluysian atrophy (DRPLA) gene in the family members, The p atients were homozygous for an allele carrying an intermediate size of CAG repeats (41 or 40 repeats) in the DRPLA gene; the parents were he terozygous for an intermediate allele and a normal allele in this gene . Homozygosity for an intermediate allele in the DRPLA gene appears to have resulted in spastic paraplegia different from any DRPLA phenotyp e.