The TGF-b1 Gene Codon 10 Polymorphism Contributes to the Genetic Predisposition to Type 1 Diabetes Mellitus in Egyptian Children,ABEER M.N. ABD EL-BAKY, HANAN M. HAMED, TAREK M. FARID, ABED SHAHATA, INASS A. EL-RASHEED, DALIA H. EL-LEBEDY and EMAN H. THABET
Abstract
Introduction: Type 1 diabetes mellitus (T1D) results from immune-mediated destruction of the insulin-producing beta cells of the pancreas. Numerous cytokines have been shown to participate in the pathogenesis of T1D. As gene polymor-phisms can influence cytokine production or function, they may potentially contribute to genetic predisposition to the disease.
Aim: To investigate the role of TGF-b1 gene codon 10 (+869 T/C) single nucleotide polymorphism (SNP) in genetic susceptibility to T1D in Egyptian children.
Subjects and Methods: The study included 85 subjects, 50 children with T1D (mean age 10.68±3.67 years), and 35 age and sex matched healthy controls. Genotyping of TGF-b 1 +869 T/C was done using Real-Time polymerase chain reaction (PCR).
Results: The frequency of the T allele was significantly higher in T1D patients than in control group (71% Vs. 38.6%, p=0.001). While the frequency of the C allele was significantly higher in healthy controls (61.4% Vs. 29%, p=0.001). Ho-mozygous T genotype frequency was significantly increased in patients compared to controls (54% Vs. 20%, p=0.001), while homozygous C genotype frequency was significantly increased in controls (42.86% Vs. 12%, p=0.001). Heterozy-gous T/C genotype frequency showed no significant difference between the two groups (p=0.76). The TT genotype was associated with an earlier onset and a longer duration of the disease compared to other genotypes (p=0.001). Patients with TC and TT genotypes had significantly higher HBA1c levels than patients with CC genotype (p=0.02).
Conclusion: TGF-b1 gene codon 10 polymorphism is associated with the development of T1D, and T variant is a genetic marker for disease susceptibility in Egyptian children.