Type 1 diabetes genetic susceptibility encoded by HLA DQB1 genes in Romania
Guja C., Guja L., Nutland S., Rance H., Sebastien M., Todd JA., Ionescu‐Tirgoviste C.
AbstractMost cases of type 1 diabetes (T1DM) are due to an immune‐mediated destruction of the pancreatic beta cells, a process that is conditioned by multiple genes and environmental factors. The main susceptibility genes are represented by the class II HLA‐DRB1 and DQB1 alleles. The aim of our study was to reconfirm the contribution of HLA‐DQB1 polymorphisms to T1DM genetic susceptibility for the Romanian population. For this, 219 Romanian T1DM families were genotyped at high resolution for HLA DQB1 using the PCR‐SSOP method (Polymerase Chain Reaction ‐ Sequence Specific Oligonucleotide Probes). Allele transmission to diabetics and unaffected siblings was studied using the Transmission Disequilibrium Test (TDT). We found an increased transmission of DQB1 *02 (77.94% transmission, PTDT= 7.18 × 10−11) and DQB1*0302 (80.95% transmission, PTDT= 2.25 × 10−10) alleles to diabetics, indicating the diabetogenic effect of these alleles. Conversely, DQB1*0301, DQB1*0603, DQB1*0602, DQB1*0601 and DQB1*05 alleles are protective, being significantly less transmitted to diabetics. In conclusion, our results confirmed the strong effect of HLA‐DQB1 alleles on diabetes risk In Romania, with some characteristics which can contribute to the low incidence of T1DM in this country.