A joint analysis of nine diabetes-related genes (MTNR1B, TCF7L2, KCNJ11, HHEX, SLC30A8, WFS1, KCNQ1, FTO, and PPARG) indicated that the weighted risk score of these diabetes risk alleles predicted impaired glucose tolerance (IGT) in females after adjustment for age, BMI and insulin sensitivity; no such association was found in males [218]. This evidence concerns the gene TCF7L2 and diabetes mellitus.