Clinical and genetic study of two families with dentatorubral-pallidoluysian atrophy / 中华实用儿科临床杂志

ABSTRACT

Objective:To study the clinical and genetics features of two families with dentatorubral-pallido-luysian atrophy (DRPLA), and to summarize the correlation between genotypes and phenotypes.Methods:The peripheral blood, clinical data and auxiliary examination results of probands and related members in 2 families with hereditary epilepsy and ataxia were collected from July 2018 to March 2019 in Peking University First Hospital.By whole exome sequencing and detecting the cytosine-adenine-guanine (CAG) repeats with capillary electrophoresis and fragment analysis, the genetic testing was conducted on the probands and their family members.The clinical and genetic characteristics of all affected members in the 2 families were also analyzed.Results:Two families were diagnosed with DRPLA.All 11 patients presented with psychomotor retardation, and 7 of them had seizures (including myoclonus, focal seizures and generalized tonic-clonic seizures, etc.). There were significant differences in clinical manifestations among different patients in the same family, and the filial generation had seizures at an earlier age with a more severe phenotype than the parental generation.The youngest onset age was 2 years old, and the largest was 45 years old.Five cases had seizures in childhood.Of the 11 patients, 5 cases were deceased, and the cause of death included seizure attacks, sudden unexpected death in epilepsy (SUDEP) and disease progression.The number of CAG repeat times in the fifth exon of the ATN1 gene were found abnormal in 6 surviving patients.The grandfather of the proband in pedigree 2 had normal clinical manifestations, but he also showed abnormal CAG repeats in the fifth exon of the ATN1 gene, which might be an intermediate allele. Conclusions:DRPLA is mainly featured by epilepsy, ataxia, psychomotor retardation and anticipation in clinical.This disease is rare in children with seizures as the first symptom, and has poor prognosis.An early diagnosis can facilitate genetic counseling.