Analysis Of CAG Repeats Expansion Of ATXN2in Eastern Chinese Patients With Amyotrophic Lateral Sclerosis

Objective:To investigate the role of the ataxin-2gene (ATXN2) intermediate-lengthpolyglutamine (polyQ) repeats between27and33in Eastern-Chinese ALS patients.Methods:394patients and900neurological healthy people were studied. Polymerase chainreaction (PCR) was used to amplify the ATXN2CAG repeats. PCR products wereseparated by8%polyacrylamide gel and confirmed by sequencing. The result wasanalyzed by SPSS17.0.Results:1. In our study, we found that19cases out of394ALS patients possessed a singleallele with intermediate-length repeat expansions,21(2.33%) of900control caseswere found to harbor1allele with intermediate-length repeat expansions(P=0.017)，meanwhile,2out of15FALS cases(P=0.052) and19of379SALS cases weredetected(P=0.038) were found to be positive with intermediate-length repeatsexpansions.2.11(2.79%) patients in394ALS group were found to harbor one allele withintermediate-length repeat expansions greater than27while only6(0.67%) of healthycontrols had it (P=0.002), and1of them are FALS (P=0.110) while10are SALS(P=0.004).3. No statistical significance was found in age on set and gender difference betweenALS patients with Intermediate-length CAG repeats expansion and patients withoutintermediate-length expansion (P>0.05).4. No alleles carrying greater than32repeats were detected in these two groups.Conclusion:1. We find that Intermediate-Length polyglutamine of ATXN2is associated with ALS,and Our finding is an evidence to support the hypothesis that ATXN2plays an important role in ALS pathogenesis.2. There is no association between the phenotype and Intermediate-Lengthpolyglutamine of ATXN2.