ABSTRACT
Objective To report the clinical and genetic characteristics of a dentatorubralpallidoluysian atrophy (DRPLA) pedigree with an onset of cognitive impairment.Methods Clinical data of this pedigree was collected.The numbers of CAG repeats in the exon 5 of atrophin-1 (ATN1) gene were analysed in the proband and the other 4 healthy family individuals.The polymerase chain reaction (PCR) products of the proband underwent cloning-sequencing using an original TA cloning kit.Results There were 5 patients in this family,4 with onset in adult and one in childhood.The proband had an onset manifestation of cognitive impairment,while the other 3 adult patients presented with ataxia.The two-year-old child in the pedigree had myoclonic epilepsy.The proband had 61 CAG repeats in the exon 5 of ATN1 gene.After TA cloning-sequencing of the proband ' s PCR products,there were 2 different numbers of CAG repeats,including 61 and 64.Conclusions The clinical manifestations of DRPLA can have obvious heterogeneity in one family.Some patients present with cognitive impairment.It is very important to test the numbers of CAG repeats of ATN1 gen for DRPLA diagnosis.Somatic mosaicism may be also observed in Chinese DRPLA patients.