Association of polymorphisms in the IL-18 and IL-12 genes with susceptibility to Type 1 diabetes in Turkish patients.
BACKGROUND
Recent studies have indicated that polymorphisms of the interleukin-18 (IL-18) and interleukin- 12 (IL-12) genes are associated with the development of Type 1 diabetes mellitus (T1DM) in some populations, but not all.


OBJECTIVE
The present study was designed to examine the roles of polymorphisms in the IL-18 promoter and IL-12p40 with respect to susceptibility to T1DM in Turkish patients.


METHODS
Ninety-one patients with T1DM and 87 unrelated healthy subjects were included in the study. The IL-18 polymorphisms at positions -607 and -137 were detected by a sequence-specific PCR method. The single nucleotide polymorphism in the IL-12p40 3' untranslated region (3'-UTR) at position +1188 was analyzed by the PCR-restriction fragment length polymorphism (RFPL) method.


RESULTS
The allelic and genotypic frequencies of the IL-18 and IL-12p40 polymorphisms did not differ significantly between subjects with T1DM and the controls (p>0.05). However, diabetic patients with the -137 (CC) genotype showed a younger onset age compared to patients with the -137 (GG) genotype (p=0.02). In addition, patients with the -607 (CC) genotype had higher levels of glycated hemoglobin (HbA1c) than patients with the -607 (AC) genotype (p=0.004). Furthermore, patients with the IL-12p40 (AC) genotype had higher HbA(1c) levels than patients with the IL-12p40 (AA) genotype (p=0.01).


CONCLUSIONS
The results of the present study show that the IL- 18 and IL-12p40 polymorphisms may have some effect on the onset age and deterioration of glycemic control in Turkish patients with T1DM.
Altinova
A E
AE
Department of Endocrinology and Metabolism, Gazi University Faculty of Medicine, Ankara, Turkey. alevaltinova@yahoo.com
Engin
D
D
Akbay
E
E
Akturk
M
M
Toruner
F
F
Ersoy
R
R
Yetkin
I
I
Arslan
M
M
D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D003922:Diabetes Mellitus, Type 1 / Q000235:genetics*; D005260:Female; D006801:Humans; D053762:Interleukin-12 Subunit p40 / Q000235:genetics*; D020382:Interleukin-18 / Q000235:genetics*; D008297:Male; D012150:Polymorphism, Restriction Fragment Length; D020641:Polymorphism, Single Nucleotide; D014421:Turkey
D053762:Interleukin-12 Subunit p40; D020382:Interleukin-18