frequency of three common mutations of CARD15/NOD2 gene in Iranian IBD patients

ABSTRACT

CARD15/NOD2 gene, located on the pericentromeric region of chromosome 16 [IBD1] has been reported to have an association with IBD, especially Crohn's disease [CD]. Many independent studies have shown a variable association between three common mutations of CARD 15, with Crohn's disease in different ethnic groups. Thus, raising the hypothesis that genetic and / or allelic heterogeneity may influence the relationship between CARD 15 and Crohn's disease. In the present study, we have investigated the frequency of three main mutations of CARD 15 gene [Arg 702 Trp, Gly 908 Arg and Leu 1007 fsinsC] in Iranian IBD patients and compared it with healthy control population. For this case-control study, 100 ulcerative colitis [UC], 40 Crohn's disease patients and 100 sex- age- and ethnicity-matched controls were enrolled from a teaching hospital during a one year period [2003-2004]. All three mutations were assessed on DNA of leukocyte cells, by PCR [Polymerase Chain Reaction] and RFLP [Restriction Fragment Length Polymorphism] methods. The mean age of UC, CD and healthy controls were 38.6 +/- 14.3, 36.6 +/- 14.1, and 38.6 +/- 14.2 years. Among the three evaluated CARD 15 gene mutations, the frequency of Arg702Trp mutation was significantly higher in Iranian patients with Crohn's disease [OR19.2; 95%CI4.2-87.3, p<0.001]. None of these mutations were associated with ulcerative colitis. This study showed that Arg702Trp mutation of CARD 15 gene is probably associated with Crohn's disease in Iranian population; indicating that genetic polymorphisms may differ between populations