No association between the -1031 polymorphism in the TNF-alpha promoter region and type 1 diabetes.
Tumor necrosis factor alpha (TNF-alpha) is an important immunomodulator and is believed to be involved in the development or progression of type 1 diabetes. In the following study, we evaluated TNF-alpha promoter polymorphisms at positions -863 and -1031 and their association with type 1 diabetes in a group of 210 diabetic patients from Lebanon. Our results show that in our population, the C allele is predominant at position -863, whereas the A allele is very rare (2%). At position -1031, however, the C and T allele distribution was similar in both the patient (17.8% vs 82.2%, respectively) and the control (21.4% vs 79.6%) groups. No association of TNF-alpha genotype at position 1031 with type 1 diabetes was found as demonstrated by the family-based association test and the transmission disequilibrium test. However, when patient genotypes were compared, the recessive CC genotype was only found in type 1 diabetic males but not in type 1 diabetic females. This observation, however, requires further investigation in a larger sample before conclusive association to gender is suggested. In conclusion, our results demonstrate that no association between TNF-alpha polymorphism and type 1 diabetes seems to exist in our population.
Shbaklo
Hadia
H
Genetics Research Laboratory, Chronic Care Center, Beirut, Lebanon.
Azar
Sami T
ST
Terwedow
Henry
H
Halaby
Georges
G
Naja
Roy P
RP
Zalloua
Pierre A
PA
D000293:Adolescent; D017668:Age of Onset; D003922:Diabetes Mellitus, Type 1 / Q000453:epidemiology / Q000235:genetics*; D005260:Female; D006683:HLA-DQ Antigens / Q000235:genetics; D059848:HLA-DQ alpha-Chains; D059866:HLA-DQ beta-Chains; D006239:Haplotypes; D006801:Humans; D008297:Male; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics*
D006683:HLA-DQ Antigens; D059848:HLA-DQ alpha-Chains; D059866:HLA-DQ beta-Chains; C069050:HLA-DQA1 antigen; C069051:HLA-DQB1 antigen; D014409:Tumor Necrosis Factor-alpha