title: Interleukin 18 promoter polymorphisms are not strongly associated with type I diabetes in a UK population.
abstract: Interleukin 18 (IL18) is a proinflammatory cytokine whose levels are increased in the subclinical stage of insulin-dependent (type I) diabetes mellitus. Previous case-control studies have reported associations between IL18 -607C>A and -137G>C promoter polymorphisms and type I diabetes. We performed case-control and family-based association studies employing Pyrosequencing to assess if these IL18 polymorphisms are also associated with the development of type I diabetes in the Northern Ireland population. The chi2 analysis of genotype and allele frequencies for the IL18 polymorphisms in cases (n=433) vs controls (n=426) revealed no significant differences (P>0.05). Assessment of allele transmission distortion from informative parents to affected offspring also failed to confirm previously reported associations. Stratification of these analyses for age-at-onset and HLA-DR type did not reveal any significance associations. In conclusion, our data do not support the strong positive associations of IL18 promoter polymorphisms with type I diabetes reported in previous smaller studies.
authors.affiliation: Department of Medical Genetics, The Queen's University of Belfast, Belfast City Hospital, Belfast, Northern Ireland. rosalind.martin@qub.ac.uk
authors.forename: R J L
authors.initials: RJ
authors.lastname: Martin
authors.forename: D A
authors.initials: DA
authors.lastname: Savage
authors.forename: D J
authors.initials: DJ
authors.lastname: Carson
authors.forename: A P
authors.initials: AP
authors.lastname: Maxwell
authors.forename: C C
authors.initials: CC
authors.lastname: Patterson
mesh_terms: D003922:Diabetes Mellitus, Type 1 / Q000235:genetics*; D005260:Female; D008040:Genetic Linkage; D020022:Genetic Predisposition to Disease; D006801:Humans; D020382:Interleukin-18 / Q000235:genetics*; D008297:Male; D020641:Polymorphism, Single Nucleotide; D011401:Promoter Regions, Genetic; D006113:United Kingdom
chemical_list: D020382:Interleukin-18