[Molecular genetics and its clinical application in the diagnosis of spinocerebellar ataxias].

Objective: To study the strategy of applying molecular genetic methods and techniques in the diagnosis of spinocerebellar ataxias (SCA).
Methods: This study included 43 patients with SCA from 36 families, 38 sporadic SCA patients, 60 healthy individuals from the SCA families and 44 normal controls. The trinucleotide repeats were detected by polymerase chain reaction (PCR), denaturing polyacrylamide gel electrophoresis and silver staining technique. The repeat numbers were calculated by software.
Results: SCA3 was the most common type in the Hans of south China, accounting for 42.0%, followed by SCA2 (7.4%), SCA1 (4.9%), SCA7 (3.7%), SCA6 (2.5%) and SCA12 (1.2%). No patient was found to have SCA8, SCA10, SCA17, and dentatorubro-pallidoluysian atrophy(DRPLA).
Conclusion: Molecular genetic detection is an effective way to confirmation of SCA subtype diagnosis and presymptomatic genetic diagnosis.