|(A;A)||2.1||lower risk of metabolic syndrome|
|(A;G)||2||lower risk of metabolic syndrome|
The most common allele is rs2229616(G); the rarer (A) allele encodes the 103I (isoleucine), and this (A) allele has been associated in a study of 8,000+ Caucasians with a significantly decreased waist circumference (-1.46 cm, p = 0.020), decreased glycosylated hemoglobin (HbA1c) (-0.09%, p = 0.040), and increased HDL-cholesterol (HDL-C) (+1.76 mg/dl, P = 0.056), but no change in blood pressure. The odds of having three or more components of the metabolic syndrome were substantially reduced among carriers of an rs2229616(A) allele (odds ratio = 0.46, p = 0.003). Basically, rs2229616(A) carriers are on average slightly leaner than rs2229616(G;G) homozygotes.[PMID 18239646]
[PMID 14973783] Melanocortin-4 receptor gene variant I103 is negatively associated with obesity.
[PMID 17357083] Medical sequencing at the extremes of human body mass.
[PMID 17519222] Non-synonymous polymorphisms in melanocortin-4 receptor protect against obesity: the two facets of a Janus obesity gene.
[PMID 18377640] Val103Ile polymorphism of the melanocortin-4 receptor gene (MC4R) in cancer cachexia.
[PMID 18454148] Common variants near MC4R are associated with fat mass, weight and risk of obesity.
[PMID 20092643] Large effects on body mass index and insulin resistance of fat mass and obesity associated gene (FTO) variants in patients with polycystic ovary syndrome (PCOS).
[PMID 20127379] From monogenic to polygenic obesity: recent advances.
[PMID 20530052] Melanocortin-4 receptor polymorphisms in Turkish pediatric obese patients.
[PMID 22020349] Polymorphisms of INSIG2, MC4R, and LEP are associated with obesity- and metabolic-related traits in schizophrenic patients.
[PMID 22310352] Genetic association study between antipsychotic-induced weight gain and the melanocortin-4 receptor gene.
|qualified_impact||Low clinical importance, Uncertain protective|
|summary||This variant was associated with a reduced incidence of obesity in a large meta-analysis of more than 55,000 individuals.|
[PMID 22989167] Association of melanocortin-4 receptor gene polymorphisms with obesity-related parameters in Malaysian Malays.