[Triplet repeat disorder, dentatorubral and pallidoluysian atrophy DRPLA)]

Dentatorubral and pallidoluysian atrophy (DRPLA) is an autosomal dominant neurodegenerative disorder characterized by combined systemic degeneration of the dentatofugal and pallidofugal pathways. The patients show a variable combination of symptoms including cerebellar ataxia, involuntary movements like chorea and athetosis, myoclonic epilepsy and dementia. We found expansion of an unstable CAG repeat in the patients, and then determined the cDNA and genomic forms of the gene, as reported in Nature Genetics 6:14-18 and 8:177-182, 1994. In this review, we summarize our studies on repeat expansion of the DRPLA gene, and discuss the common and distinctive features among triplet repeat disorders.