Objective: To investigate the clinical manifestations and gene mutations on a large spinocerebellar ataxia 3 pedigree, in order to explore the molecular genetical characteristics in this pedigree.
Methods: Blood samples from 9 patients and 27 healthy family members in the Department of Neurology of Henan Provincial People's Hospital were collected. The CAG trinucleotide repeats in SCA3 gene in each sample were amplified by polymerase chain reaction (PCR), denaturing polyacrylamide gel electrophoresis and silver staining techniques. The allele fragments were sequenced by biomedical company and the trinucleotide repeats numbers were calculated to identify the genotype.
Results: Nine symptomatic and 9 presymptomatic patients were detected and their CAG repeat numbers were 62-72 and 63-69, respectively. CAG repeat numbers were 12-21 in the other 18 healthy family members.
Conclusions: We found a large pedigree with the diagnosis of SCA3. The genetic tests of CAG repeat numbers can contribute to clinical diagnose on symptomatic patients and provide informations for presymptomatic patients.