MC4R and metabolic syndrome: Efforts of genetic studies to find the reason for co-occurrence of Mets components led to investigating the likelihood of a role for the A allele of rs12970134, a variant in the melanocortin-4 receptor (MC4R) gene, in the development of MetS [3–5]; however, there are some studies that found no such relationship between variants in the MC4R gene and this syndrome [6, 7].