Association between cytokine genes polymorphisms and type 1 diabetes: a case-control study on Saudi population

ABSTRACT

Background: Association studies of genes encoding cytokines that play an important role in inflammatory response represent one approach to finding type 1 diabetes (T1D) disease genes. The aim of this study was to investigate the association of single nucleotide polymorphisms (SNPs) within cytokine genes with T1D in a cohort of Saudi subjects. Methods: A total of 300 well-characterized type 1 diabetic patients and 300 T1D-free control subjects were enrolled in this investigation. Cytokine SNPs were genotyped by using Polymerase chain reaction (PCR) with sequence-specific primers. Results: Our data revealed that IFN-γ +874T allele carriers [odds ratio (OR) = 1.87, p < 0.001] and TT homozygotes (OR = 1.28, p < 0.001) were significantly more susceptible to developing T1D than the A allele carriers. In addition, TNF-α −308A allele carriers (OR = 1.73, p < 0.001) and AA homozygotes (OR = 1.74, p < 0.001) were also overrepresented among the diabetics than G allele carriers. IL-4 −590C/T TT homozygotes (OR = 2.23, p < 0.001) were significantly more susceptible to develop T1D than CC genotypes, whereas CT heterozygotes were not significantly associated (OR = 1.43, p = 0.78) with T1D. Furthermore, IL-4 T allele was statistically associated with T1D patients compared to control group (OR = 2.24, p < 0.001). Similarly, IL-1β −511C/T TT homozygotes (OR = 1.85, p = 0.012) and the T allele (OR = 1.85, p < 0.001) were significantly more susceptible to T1D than CC genotypes, whereas TC heterozygotes (OR = 1.04, p = 0.86) were not significantly associated with T1D. Conclusion: Our data concluded that IFN-γ +874T allele, TNF-α −308A allele, IL-1β −511T allele, and IL-4 −590T allele could be considered risk factors for T1D development in Saudi subjects.

KEYWORDS:

• Type 1 diabetes
• cytokine genes polymorphisms
• Saudi population

Declaration of interest

The authors declare that they have no conflict of interest.

Additional information

Funding

This work was financially supported by research grant from Taif University, Kingdom of Saudi Arabia: [Grant Number 1-437-4759].