Identification of +49A/G polymorphism of cytotoxic T lymphocyte-associated protein-4 gene in type 1 diabetes patients in Kerbala province/Iraq

Abstract

BackgroundType 1 diabetes mellitus (T1DM) is an insulin-dependent form of diabetes associated with progressively increasing morbidity and mortality across the globe. Cytotoxic T lymphocyte antigen-4 (CTLA-4) encoded by the CTLA-4 gene on chromosome 2q33 has an important role in homeostasis and negative regulation of immune responses. Therefore, CTLA-4 gene polymorphisms are considered to be a key element in the development of T1DM. Aim of the studyThe study aimed to elucidate the contribution of cytotoxic T-lymphocyte antigen-4 (+49 A/G) polymorphism of CTLA-4 gene to the susceptibility T1DM. MethodsA present case-control study was designed to include 120 Iraqi children with T1DM and 120 healthy children as a control group. The patients were diagnosed previously with T1DM by Al-Imam Al-Hassan center for endocrine and diabetes in Al-Imam Al-Hussein medical city in holy Kerbala province.Genotyping CTLA-4 (+49A/G) gene was performed using tetra-primer amplification refractory mutation system-polymerase chain reaction technique (T-ARMS-PCR). ResultsRisk factors of T1DM (Family history of diabetes mellitus, age at onset, gender) were found to be an independent risk factor for T1DM P value >0.05.The AG genotype significantly raised the risk of T1DM by more than six folds (OR = 6.7, 95% CI; 3.63–12.29, P < 0.05). While the G allele significantly raised the risk of T1DM by more than two folds (OR = 2.8, 95% CI; 1.88–4.15, P < 0.05). In addition to the GG genotype also was significantly (OR = 7.76, CI 95% = 2.16–27.88, P < 0.05) changed among the two groups. ConclusionOur case-control study suggests that the CTLA-4 (+49A/G) gene polymorphism is associated with T1DM in the Kerbala children.