Absence of genetic variation in some obesity candidate genes (GLP1R, ASIP,MC4R MC5R) among Pima Indians

OBJECTIVE: To examine the obesity candidate genes glucagon-like-peptide rec eptor (GLP1R), agouti signaling protein (ASlP) and the melanocortin recepto rs 4 and 5 (MC4R and MC5R) for DNA polymorphisms in their coding regions. SUBJECTS: Unrelated, non-diabetic Pima Indians (8 to 12 from each extreme o f body fat). MEASUREMENTS: DNA sequencing within the coding regions of each gene. RESULT : Only one variant was detected, a silent substitution in exon 6 of GLP1R. CONCLUSION: The exclusion of any common amino-acid polymorphisms (allele fr equency greater than or equal to 0.20). implies that structural variants of these genes do not contribute to variation in the high level of obesity ob served among the Pima Indians.