Distribution of different genotypes of hereditary ataxia in south China

Qiuyou XIE; Xiuling LIANG; Xunhua LI

ABSTRACT

BACKGROUND:

It is of great importance to study the genotype distribution of hereditary ataxia in understanding its epidemiologic rule and pathogenetic pathway.

OBJECTIVE:

To analyze the distribution of different genotype of hereditary ataxia in south China.

DESIGN:

A case-control observation.

SETTING:

Department of Neurology, the First Affiliated Hospital of Sun Yat-sen University.

PARTICIPANTS:

Forty-three patients (26 males and 17 females) with hereditary ataxia from 36 families and 38 patients with sporadic hereditary ataxia (24 males and 14 females) were selected from the Outpatient Clinic of Neurogenetics, Department of Neurology, the First Affiliated Hospital of Sun Yat-sen University between September 1998 and September 2002. At the same time, 60 healthy individuals from the patients' families and 44randomly-selected healthy physical examinees were taken as controls. All the participants were enrolled voluntarily.

METHODS:

The fragments of trinucleotide repeats at different sites of mutant genes were amplified with polymerase chain reaction (PCR), and then the lengths were calculated with polyacrylamide gel electrophoresis and imaging analytical software. The repeated numbers of trinucleotide repeats in all the normal and abnormal amplified alleles were calculated respectively.MAIN OUTCOME

MEASURES:

Different genotype distribution in patients with hereditary ataxia.

RESULTS:

All the subjects were involved in the analysis of results. Of the detected patients with hereditary ataxia, the Machado-Joseph disease/spinocerebellar ataxia (SCA) 3 was the most common type of autosomal dominant SCA in South China, which was 42.0%, and was followed by SCA2 (7.4%), SCA1 (4.9%), SCA7 (3.7%), SCA6 (2.5%), SCA12 (1.2%).No patient was detected to have SCA8 SCA 10, SCA 17 dentatorubropallidoluysian atrophy (DRPLA) and Friedreich ataxia (FRDA).

CONCLUSION:

Autosomal dominant SCA3 is the most familiar genotype in South China. Clinical detection of hereditary ataxia should be done firstly aiming at the SCA3 genotype.