Genetic association of type 1 diabetes in an Azerbaijanian population: the HLA-DQ, -DRB1*04, the insulin gene, and CTLA4.
BACKGROUND
Little is known on the genetic susceptibility to type 1 diabetes mellitus (T1DM) in the nations of the former Soviet part of south-west Asia.


OBJECTIVE
The aim of the study was to characterize the genetic association of T1DM in the Azeri, the majority population of Azerbaijan.


METHODS
One hundred and sixty patients with childhood-onset T1DM, and 271 healthy unrelated controls were compared in a case-control study. All declared themselves as Azeri. The human leukocyte antigen (HLA)-DQB1, -DQA1 alelles, of DRB1*04 subtypes, and of insulin gene and cytotoxic T-lymphocyte-associated protein 4 (CTLA4) single nucleotide polymorphisms were determined using polymerase chain reaction (PCR) techniques, the association was tested from cross-tabulations, and quantified using odds ratios (OR). In the non-HLA factors, analyses were also stratified according to the HLA-conferred risk.


RESULTS
Risk for T1DM was associated with presence of the HLA-DQB1*02-DQA1*05, OR = 6.6 [95% confidence interval (CI) 4.3-10], the HLA-DQB1*0302-DQA1*03, OR = 3.9 (95% CI 2.6-6.0), and an unexpectedly high risk was observed for DQB1*0304, OR = 10.9, but the very wide CI (CI 95% 2.4-49) prompts careful interpretation. A negative association with diabetes was observed for the DQB1*0602, 0503, 0301, and 0601 alleles, as well as the DRB1*0403 subtype. A strong protection was also associated with the less frequent variant of the insulin gene (OR of the phenotypic positivity was 0.28, CI 95% 0.17-0.46), while the CTLA4 +49 A/G transition was not associated with T1DM.


CONCLUSIONS
We bring the first report on both HLA, and non-HLA association of T1DM from the majority Azeri population of Azerbaijan.
Ahmedov
Gunduz
G
Azerbaijan Medical University, Str. K. Ragimov 11, Baku, Azerbaijan Republic.
Ahmedova
Leyla
L
Sedlakova
Pavlina
P
Cinek
Ondrej
O
D017668:Age of Onset; D015703:Antigens, CD; D000943:Antigens, Differentiation / Q000235:genetics*; D060908:CTLA-4 Antigen; D016022:Case-Control Studies; D002648:Child; D018153:Czech Republic / Q000453:epidemiology; D003922:Diabetes Mellitus, Type 1 / Q000235:genetics*; D005260:Female; D006683:HLA-DQ Antigens / Q000235:genetics*; D006684:HLA-DR Antigens / Q000235:genetics*; D059811:HLA-DRB1 Chains; D006801:Humans; D007328:Insulin / Q000235:genetics*; D008297:Male
D015703:Antigens, CD; D000943:Antigens, Differentiation; D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human; D006683:HLA-DQ Antigens; D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains; D007328:Insulin