Association of CTLA-4 gene polymorphism in Jordanian type 1 diabetic patients

Objective: to study the association between type 1 diabetes and the allelic polymorphism of the ctla-4 gene in a jordanian population. methodology : we studied 50 jordanian type 1 diabetes and 50 normal subjects to determine the association between the snps a/g and -c/t and type 1 diabetes. results: the frequency of genotype for heterozygous ag= 42%,homozygous wild type allele aa= 50%. homozygous mutant allele gg=8%,wild allele a=7%,and for mutant allele g=29%,with unknown clinical findings but the frequency of phenotype for wild allele a=92% and mutant allele g= 6%; a=74%,g=26%,a=94% and g=16% respectively. with distribution of ctla-4 + 49 a/g genotype frequency did not differ significantly between patient and control (p=0.885). the result on the other snp-318 c/t. showing the frequency of genotype; for heterozygous( ct=16%),homozygous wild allele (cc=84%),homozygous genotype for t allele =0%. normal allele c=92%,but for mutant allele is (t=8%) with unknown clinical finding,where the phenotype for wild allele is (c=100%),phenotype mutant allele is t=16%. on the other hand for control subject investigated for ctla-4 -318 c/t polymorphism (ct=22%,cc=74%,tt=4%,c=85%,t=15%,c=96%,t=26%) respectively. the result of distribution of ctla-4 -318 c/t genotype frequency did not differ significantly with tid patient and controls (p=0.248) conclusion: this case-control study suggest that the +49 a/g snp of the ctla-4 gene is not strongly associated with type one diabetes mellitus in jordanian population,the apparent discrepancies between the present study and other studies could be due to the genetic heterogeneity among the population studied. the ctla-4 49 a/g snp may not be the true disease associated variant but a marker in linkage disequilibrium in different population.