MTHFR and obesity due to melanocortin 4 receptor deficiency: We studied the association between five obesity and co-morbidities-related genetic variants (IGF2BP2 rs4402960, LPL rs320, LPL rs328, KCJN rs5219, and MTHFR rs1801133) and athletic status in a well-defined (athletic level, ethnicity, gender) athletic population.