Notably, we identified a heterozygous RCN2 nonsense variant that co-segregated with obesity within a specific family, as indicated by this RCN2 variant observed in the proband with obesity (II2) and two other family members with obesity (II3 and III2) but not in other family members (Fig. 7a, b). This evidence concerns the gene RCN2 and obesity due to melanocortin 4 receptor deficiency.