Association of SLC22A4 and TNF-α gene polymorphism with susceptibility to inflammatory bowel disease among patients in the Eastern Province of Saudi Arabia.

BACKGROUND

Inflammatory bowel disease (IBD) is a term referring to gastrointestinal chronic inflammatory disorders. Ulcerative Colitis (UC) and Crohn's Disease (CD) are the two main types of IBD. The aetiology of such disease has been attributed to many factors: aside from the influence of the environment, genetic factors in particular play a significant role in disease progression. Genetic variants C1672T (SLC22A4), G-207C (SLC22A5) G113A, C4136A, 35delA (DLG5) and (rs1799964) TNF-α have been reported to have significant associations with the development of IBD in various populations.

AIM: This study investigated the association of rs1799964 (TNF-α) and rs1050152 (SLC22A4) with IBD risk among patients in Kingdom of Saudi Arabia (KSA).

METHODS

A study sample (n = 81) was collected from King Fahad University Hospital (KFUH), in the Eastern province of KSA, that included 41 IBD patients (CD = 23, UC = 18) and 40 healthy controls. All subjects were genotyped using real-time PCR based TaqMan chemistry.

RESULTS

The results showed that rs1799964 SNP was significantly associated with IBD in terms of C allele frequency (P < 0.0001; OR 11.42, 95 %CI 5.48-23.79) and CC genotype frequency (P < 0.0001; OR 149.5, 95 %CI 15.56-1435.58). A significant association was also found in rs1050152 SNP based on the frequency of the T allele (P < 0.0107; OR 39.94, 95 %CI 2.35-678.43). In terms of genotype frequency, the CT genotype and additive model (CT + TT) were also associated with IBD (p = 0.01).

CONCLUSION

The significantly associated SNPs of TNF-α and SLC22A4 genes suggest a potential genetic basis for assessing IBD susceptibility in Saudi patients. Further studies from other regions may provide better understanding of disease pathogenesis in relation to genetic association.