The TGF-β1 Gene Codon 10 Polymorphism Contributes to the Genetic Predisposition to Type 1 Diabetes Mellitus in Egyptian Children

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 polymorphisms can influence cytokine production or function, they may potentially contribute to genetic predisposition to the disease. Aim: To investigate the role of TGF-β1 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-β 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). Heterozygous 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-β1 gene codon 10 polymorphism is associated with the development of T1D, and T variant is a genetic marker for disease susceptibility in Egyptian children.