A good example is the peroxisome proliferator-activated receptor gamma coactivator1α (PPARGC1A) Gly482Ser polymorphism, in which the 482Ser allele is associated with increased risk of obesity and type 2 diabetes [20], whereas the ‘favourable’ Gly482 allele is associated with elite athletic performance [21]–[24]. The gene discussed is PPARGC1A; the disease is type 2 diabetes mellitus.