Toward Further Mapping of the Association Between the IL2RA Locus and Type 1 Diabetes
- 1Endocrine Genetics Laboratory, McGill University Health Center (Montréal Children's Hospital), Montréal, Québec, Canada
- 2McGill University and Genome Québec Innovation Centre, Montréal, Québec, Canada
- Address correspondence and reprint requests to Dr. Constantin Polychronakos McGill University Health Center (Montréal Children's Hospital), 2300 Tupper, Montréal, Qc H3H 1P3, Canada. E-mail: constantin.polychronakos{at}mcgill.ca
Abstract
A novel type 1 diabetes locus was mapped to the interleukin-2 receptor α gene (IL2RA) on chromosome 10p15.1, encoding an important modulator of immunity. The aim of the current study was to confirm the association of IL2RA with type 1 diabetes and to attempt further mapping of the genetic effect with a new set of 12 single nucleotide polymorphisms (SNPs). We genotyped 949 nuclear family trios with one type 1 diabetes–affected offspring and two parents (2,847 individuals). Two of the 12 IL2RA SNPs genotyped (rs706778 and rs3118470) had statistically significant type 1 diabetes association (P = 6.96 × 10−4 and 8.63 × 10−4, respectively). Both SNPs are located in the 5′ end of the long intron 1 within 3 kb of each other and are in high linkage disequilibrium (D′ = 0.997, r2 = 0.613). The A-C haplotype (frequency = 0.331) was associated with increased type 1 diabetes risk (P = 3.02 × 10−4). Our study identifies two markers in the IL2RA gene that are significantly associated with type 1 diabetes, supporting IL2RA as a promising candidate gene for type 1 diabetes and suggesting a potential role of IL2Rα in the pathogenesis of type 1 diabetes, likely involving regulatory T-cells.
Footnotes
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Additional information for this article can be found in an online appendix at http://dx.doi.org/10.2337/db06-1555.
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The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
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- Accepted December 21, 2006.
- Received November 7, 2006.
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