Association analysis of the AIRE and insulin genes in Finnish type 1 diabetic patients.
Mutations in the autoimmune regulator (AIRE) gene cause a recessive Mendelian disorder autoimmune polyendocrinopathy syndrome type 1 (APS-1 or autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy). APS-1 patients develop multiorgan autoimmune diseases including type 1 diabetes (prevalence 12%). The AIRE protein controls the central tolerance induction in the thymus by regulating the expression levels of tissue-specific peripheral antigens, such as insulin. We hypothesized that the insulin gene (INS) polymorphisms together with the AIRE variations may predispose individuals to diabetes. The role of the AIRE gene was tested both independently and on the condition of the INS risk genotype in the Finnish type 1 diabetes sample. A total of 733 type 1 diabetic cases and 735 age- and sex-matched healthy controls were used in the analysis. Five common single nucleotide polymorphisms (SNPs) in the AIRE gene were selected from the public database (dbSNP). The -23HphI polymorphism was used as a surrogate marker for the INS gene promoter repeat. The five genotyped SNPs in the AIRE gene showed no evidence of association with type 1 diabetes. As expected, the INS gene polymorphism -23HphI was significantly associated with susceptibility to type 1 diabetes (P=6.8 x 10(-12), chi(2) test). When the subclass of patients carrying the homozygote genotype of the INS gene was used in the analysis, the AIRE polymorphisms showed no association with the disease. In conclusion, the AIRE gene does not seem to contribute to disease susceptibility in Finnish type 1 diabetic patients, whereas the insulin gene represents a notable risk factor for disease in this population.
Folkhälsan Institute of Genetics, Folkhälsan Research Center, Biomedicum Helsinki (C318b), University of Helsinki, P.O. Box 63, Haartmaninkatu 8, 00014, Helsinki, Finland.
Joni A
JA
Turunen
Maija
M
Wessman
Carol
C
Forsblom
Riika
R
Kilpikari
Maija
M
Parkkonen
Nora
N
Pöntynen
Tanja
T
Ilmarinen
Ismo
I
Ulmanen
Leena
L
Peltonen
Per-Henrik
PH
Groop
D000328:Adult; D003922:Diabetes Mellitus, Type 1 / Q000235:genetics*; D005260:Female; D005387:Finland; D020022:Genetic Predisposition to Disease; D006801:Humans; D007328:Insulin / Q000235:genetics*; D015810:Linkage Disequilibrium; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D014157:Transcription Factors / Q000235:genetics*; D000096927:AIRE Protein
D007328:Insulin; D014157:Transcription Factors; D000096927:AIRE Protein