Molecular scanning for mutations in the melanocortin‐4 receptor gene in obese/diabetic Japanese

Abstract

Decreased function of the melanocortin‐4 receptor (MC4R) was reported to cause late‐onset obesity and insulin resistance in rodents. Thus mutations in the MC4R gene drew strong attention as a possible cause of obesity and diabetes. We screened for mutations in the MC4R gene in extremely obese [body mass index (BMI) ≥ 35 kg/m 2 ] Japanese with diabetes by direct sequencing. A heterozygous mutation (V103I) was detected in one case (2.0 %), however the frequency was not significantly different from that in non‐obese (BMI ≤ 24 kg/m 2 ) and non‐diabetic subjects (2.7 %). No other mutations were detected. These results suggest that mutations including V103I in the MC4R gene are not a major cause of obesity or diabetes in Japanese.