Gene polymorphisms of TNF-α⁻³⁰⁸ (G/A), IL-10⁻¹⁰⁸² (G/A), IL-6⁻¹⁷⁴ (G/C) and IL-1Ra (VNTR) in Egyptian cases with type 1 diabetes mellitus

Abstract

Background. Type 1 diabetes (T1D) is a genetically conditioned autoimmune disease in which cytokines play an important role.

Objectives. To check for the association of polymorphisms of cytokine genes with type 1 diabetes.

Subjects. This work included 50 cases with T1D and 98 healthy individuals from the Nile Delta region of Egypt. Cases included 20 males and 30 females with a median age of 25 and range of 15–50 years.

Methods. DNA was amplified using PCR with sequence-specific primers for detection of polymorphisms related to tumor necrosis factor (TNF)-α^{− 308} (G/A), interleukin (IL)-10^{− 1082} (G/A), IL-6^{− 174} (G/C), and IL-1Ra (VNTR).

Results. Cases with T1D showed significant higher frequency of genotypes of TNF-α^{− 308} AA (p < 0.001, odds ratio (OR) = 7.91), IL-6-17CC (p < 0.05, OR = 3.36) and IL-1Ra A1A1 (p < 0.05, OR = 3.68) with significant lower frequencies of TNF-α^{− 308} GA, and IL-1Ra A1A2 genotypes (p < 0.001 and < 0.05, respectively). They also showed significant higher frequency of TNF-α^{− 308} allele A (p < 0.05, OR = 2.0), IL-1Ra allele A1 (p < 0.05, OR = 2.98) with a significant lower frequency of TNF-α^{− 308} G allele and IL-1Ra A2 allele (p < 0.05). No significant difference was detected among cases in relation to IL-10^{− 1082} (G/A) genotypes or alleles nor in relation to age, sex, consanguinity or family history of the disease.

Conclusions. Polymorphisms related to TNF-α and IL-1Ra genes may be considered genetic markers for T1D among Egyptians with a potential impact on family counseling and management.

• Type 1 diabetes
• cytokines
• gene polymorphism
• Egypt

Declaration of interest: Authors declare absolute freedom of any conflict of interest related to this work.