Genetic diagnosis of Huntington's disease: cases report

摘要

Objective:To assess the efficiency of the PCR combined DNA sequencing to ascertain CAG repeat size of Huntington's disease(HD)gene as for gene diagnosis of HD.Method:Three patients with HD were diagnosed genetically with the technology of polymerase chain reaction (PCR) and polyacrylamide gel electrophoresis by assessing the CAG repeat size of HD gene.DNA sequencing then was used as verification test for HD gene.Results:Nine members of three nuclear families were included in this study,three patients were HD proband.In those families,CAG repeats of all spouse of propositus were in normal range.CAG repeats of all propositus and their descendants with the normal allele were in normal range,while CAG copy number of the other mobigenous allele was obviously abnormal.Conclusion:PCR combined DNA sequencing can be used to effectively ascertain CAG repeat of HD gene.CAG-repeat expansion mutations were accounted for 99％ of HD cases,so HD can be accurately diagnosed by this method.