Studies On The Association Of CTLA-4 Gene Microsatellite Polymorphism With Graves Disease Of Zhuang And Han Nationality In Guangxi Province

Objective: To investigate the relationship between the polymorphic (AT)n repeats in the 3'untranslated region of exon 4 of CTLA-4 gene[CTLA-4(AT)n] and Graves disease (GD)of Zhuang nationality and Han nationality in Guangxi. Methods: The study group comprised 112 patients with Graves disease and 94 normal controls, matched with patients for sex, age. Amplification of target DNA was carried out by the polymerase chain reaction(PCR) ,with primers 5'-GCC AGT GAT GCT AAA GGT TG -3'and 5'-AAC ATA CGT GGC TCT ATG CA -3'. The amplified products were electrophoresed by 8% polyacrylamid gel and followed by 0.1% silver staining. Some of the amplified products were sequenced directly. Results:19 alleles of CTLA-4 gene microsatellite polymerphism were found in Guangxi zhuang nationality individuals.But there were only 18 alleles of CTLA-4 gene microsatellite polymorphism in han nationality individuals. Long allele, 106bp was apparently increased in patients with GD in Zhuang nationality and Han nationality compared with healthy controls (P﹤0.05). The 104bp allele in health control was higher than GD patients of Han nationality in Guangx(iP=0.01). But the same was not found in Zhuang nationality individuals. Conclusion : CTLA-4 gene microsatellite polymorphism was strongly associated with GD patients of Han and Zhuang nationality in Guangxi province. CTLA-4 (AT)n 106bp may be the susceptible gene in GD patients of Han and Zhuang nationality in Guangxi. CTLA-4 (AT)n 104bp may be the protective factor in GD patients of Han nationality.