The clinical importance of some biological markers for the risk of TIDM in Egypt

Background: Type 1 diabetes mellitus (T1DM) is a polygenic disease caused by multiple susceptibility and protective alleles interacting with each other. However, studies showed that the genes responsible for more than 50% of the genetic predisposition to T1DM, are located in the human leukocyte antigen (HLA) region on chromosome 6. Out of all three HLA classes, the HLA class II loci DQA1, DQB1 and DRB1 contribute most to the genetic predisposition to T1DM. This study determines the HLA-DRB1 allele association with susceptibility and protection to T1DM in Egyptian children. Results: The study is a HLA-Class II-DRB1 allele typing, which was carried out with polymerase chain reaction -sequence specific primer. It was conducted on 61 unrelated Egyptian children with T1DM, and 19 unrelated age- and sex- matched healthy subjects. Results of the HLA typing confirmed a positive association of the following alleles with T1DM; DRB1*03:01:01:01, DRB1*03:01:06, DRB1*03:01:12, DRB1*03:01:16, DRB1*03:07, DRB1*03:08, DRB1*03:10, DRB1*03:12, DRB1*03:42, DRB1*03:76, DRB1*03:86, DRB1*08:17, DRB1*11:07, DRB1*11:08:01, DRB1*11:23, DRB1*11:36, DRB1*11:67, DRB1*12:12, DRB1*13:144, DRB1*13:154, DRB1*13:18, DRB1*13:119, DRB1*13:146 and DRB1*15:21. On the other hand, protection against T1DM was conferred by the HLA DRB1*01:03, DRB1*13:45, DRB1*14:04, DRB1*14:31 and DRB1*15:62 alleles. Conclusion: Increased frequencies of certain HLA-DRB1 alleles, known to be positively associated with T1DM, which are consistent with other studies. In addition to the well known alleles, our study confirmed the association of some other alleles that might be unique for Egyptians. However, the protective effect of previously reported alleles was not confirmed, instead other HLA-DRB1 alleles are now in question