Effect of sequence variants on variance in glucose levels predicts type 2 diabetes risk and accounts for heritability

Nature Genetics 49, 1398 (2017). doi:10.1038/ng.3928 Authors: Erna V Ivarsdottir, Valgerdur Steinthorsdottir, Maryam S Daneshpour, Gudmar Thorleifsson, Patrick Sulem, Hilma Holm, Snaevar Sigurdsson, Astradur B Hreidarsson, Gunnar Sigurdsson, Ragnar Bjarnason, Arni V Thorsson, Rafn Benediktsson, Gudmundur Eyjolfsson, Olof Sigurdardottir, Isleifur Olafsson, Sirous Zeinali, Fereidoun Azizi, Unnur Thorsteinsdottir, Daniel F Gudbjartsson & Kari Stefansson Sequence variants that affect mean fasting glucose levels do not necessarily affect risk for type 2 diabetes (T2D). We assessed the effects of 36 reported glucose-associated sequence variants on between- and within-subject variance in fasting glucose levels in 69,142 Icelanders. The variant in TCF7L2 that increases fasting glucose levels increases between-subject variance (5.7% per allele, P = 4.2 × 10−10), whereas variants in GCK and G6PC2 that increase fasting glucose levels decrease between-subject variance (7.5% per allele, P = 4.9 × 10−11 and 7.3% per allele, P = 7.5 × 10−18, respectively). Variants that increase mean and between-subject variance in fasting glucose levels tend to increase T2D risk, whereas those that increase the mean but reduce variance do not (r2 = 0.61). The variants that increase between-subject variance increase fasting glucose heritability estimates. Intuitively, our results show that increasing the mean and variance of glucose levels is more likely to cause...
Source: Nature Genetics - Category: Genetics & Stem Cells Authors: Tags: Letter Source Type: research