Abstract

PROMOTER -318C ?T AND EXON-1 +49A?G POLYMORPHISMS OF CTLA-4 GENE CONFER SUSCEPTIBILITY TO GRAVES' DISEASE IN IRAQI POPULATION

Ismail A. Abdul-Hassan*, Suad A. Saad, Mayasah M. Khalid

Abstract

The present study was carried out in Genetic Engineering and biotechnology Institute- University of Baghdad during a period from November to May 2014, for detecting the association of -318C/T and +49A/G SNPs in CTLA-4 gene with the incidence of Graves’ disease in Iraqi patients. Genomic DNA was extracted by using Geneaid DNA extraction kit from the whole blood; PCR-RFLP was used to detect the -318C/T and +49A/G SNPs in CTLA-4 gene by using specific primers and restriction enzymes (Tru9I and BbvI, respectively). The study samples consisted of 40 patients with Graves’ disease who recruited from Endocrinology and Diabetes Centre /Al-Kindy Hospital and 40 apparently healthy individuals. This study aimed to evaluate possible association between these polymorphisms in the CTLA-4 gene (- 318C/T and +49A/G), and GD incidence in Iraqi population.The results showed no significant differences in the genotypes distribution of -318C/T and +49A/G (exon 1 between control and GD. Both -318C/T and +49A/G SNPs showed no association with GD incidence. Statistically significant for A/A homozygous normal (p ≤ 0.05), A/G heterozygous mutant (p ≤ 0.01) but no significant differences in the genotype GG homozygous mutant (p ≤ 0.5). The results also showed high GD incidence within the age group 31-50 years old with high prevalence in females than males, so that positive family history in GD was 24 (60%) out of 40 cases, the mean for the duration of disease in the patients was 4.77 years.

Keywords: Graves' disease, CTLA-4, -318C/T, +49A/G.