FREQUENCY OF HLA-DRB1/DQB1 ALLELES AMONG TYPE 1 DIABETES PATIENTS IN DUHOK, KURDISTAN REGION (IRAQ)

Abstract

Background: A large number of studies have demonstrated that specific alleles at the HLA-DRB1 andHLA- DQB1 loci are strongly associated with type 1 diabetes mellitus (T1DM). This preliminary study investigated the heterogeneity in HLA class 11 genotypes distribution among Kurd patients with type 1 diabetes.Patients and Methods: The study was conducted at Duhok Diabetes Center, Duhok, Kurdistan Region (Iraq). The study participants comprised 96 unrelated T1DM patients and 48 healthy control subjects. Currently, HLA typing methods are relatively expensive and time consuming. We sought to determine the minimum number of HLA polymorphism among T1DM patients and healthy controls that could define the HLA-DR/DQ alleles relevant to T1DM patients .All participants were typed at a polymerase chain reaction-(PCR) for theDRB1 and DQB1 loci. The association analysis was performed by comparing the frequency of DR/DQ alleles among the diabetic patients with the frequency of alleles in the healthy controls.Results: Number of specific DR/DQ alleles has been identified and a statistically significant association with diabetes has been established. Compared with the healthy controls, patients were more than two-third as likely to have HLA- DRB1*03and -DRB1*04. HLA- DQB1*02allele was also more frequent in T1DM patients. HLA-DRB1*01,-DQB1*05 and -DQB1*06 were less frequent in T1DM patients.Conclusions: The data indicate that the HLA-DRB1*03, -DRB1*04 and -DQB1*02 were positively associated with TID and may be the most prone alleles, while the HLA-DRB1*01 followed by-DQB1*05 and -DQB1*06 were negatively associated with TID and may be the most protective alleles.