We recently described an association between risk of type 2diabetes and variants in the transcription factor 7-like 2 gene (TCF7L2; formerly TCF4), with a population attributable risk (PAR) of 17%–28% in three populations of European ancestry1. Here, we refine the definition of the TCF7L2 type 2diabetes risk variant, HapBT2D, to the ancestral T allele of a SNP, rs7903146, through replication in West African and Danish type 2 diabetes case-control studies and an expanded Icelandic study. We also identify another variant of the same gene, HapA, that shows evidence of positive selection in East Asian, European and West African populations. Notably, HapA shows a suggestive association with body mass index and altered concentrations of the hunger-satiety hormones ghrelin and leptin in males, indicating that the selective advantage of HapA may have been mediated through effects on energy metabolism.
Access optionsAccess options
Subscribe to Journal
Get full journal access for 1 year
only $18.75 per issue
All prices are NET prices.
VAT will be added later in the checkout.
Rent or Buy article
Get time limited or full article access on ReadCube.
All prices are NET prices.
We thank all the individuals that provided DNA samples and other information that made this study possible. A.H., H.S. and J.H. were supported by the German National Genome Network. O.P., T.H., G.A., K.B.-J. and T.J. were supported by the Danish Medical Research Council, the Danish Diabetes Association and the European Economic Community (EUGENE 2 LSHM-CT-2004-512013). Support for the Africa America Diabetes Mellitus (AADM) study is provided by NIH grant 3T37TW00041-03S2 from the Office of Research on Minority Health. This project is also supported in part by the National Center for Research Resources (NCRR), the National Human Genome Research Institute (NHGRI) and by the National Institute for Diabetes and Digestive and Kidney Diseases (grant DK-54001). Requests for materials should be addressed to A.H. (firstname.lastname@example.org) or K.S. (email@example.com).
The structure of LD across a 545-kb region containing the TCF7L2 gene.
Comparing the risk of different rs7903146 and DG10S478 and rs7903146 and rs12255372 haplotypes.
Observed and expected rEHH values for HapMap population samples based on three demographic scenarios.
Association of type 2 diabetes risk with the markers DG10S478, rs12255372 and rs7903146 in West African subgroups.
Association of HapBT2D with 14 phenotypic traits linked to energy metabolism in Icelandic controls.
Ancestral states and frequencies of 42 SNPs used in FST selection analyses.
Demographic settings used in coalescent simulations.
Interpolated recombination map positions and minor allele frequencies.