MTCH2 and obesity due to melanocortin 4 receptor deficiency: Compared to the obesity-risk-allele score based on eight genetic variants, an extended obesity-risk-allele score based on ten variants (i.e., including genotypes at SH2B1 and MTCH2, which were individually unrelated to childhood BMI) showed very similar, but slightly attenuated, associations with childhood body size and body composition (Table S4).