Association of the low-density lipoprotein receptor gene with obesity in Native American populations

Five low-density lipoprotein receptor gene (LDLR) restriction fragment leng th polymorphisms (RFLPs: TaqI, intron 4; HincII, exon 12; AvaII, exon 13; M spI and NcoI, exon 18) were investigated in 131 individuals from five Brazi lian Indian tribes. All markers were polymorphic in this ethnic group. In t he whole sample of Amerindians, 13 (41%) of the 32 expected haplotypes were identified, but only three were shared by all tribes. The Xavante, Surui, Zoro, and Gaviao tribes, who had been studied for anthropometry, were group ed according to their genotypes, and the corresponding mean values were exa mined. Significant associations were observed between HincII *H-, AvaII *A, MspI *M-, and NcoI *N+ and the body mass index (BMI), triceps and subscap ular skinfolds, and the arm fat index (AFI). Haplotypes were derived for th ese four RFLPs, and (*H-/*A+/*M-/*N+) haplotype carriers were compared with noncarriers of this haplotype with equally significant results for the thr ee parameters (BMI, P=0.021; skinfold thickness, P<0.001; AFI, P=0.005). Th ese results suggest that the LDLR gene has some influence over adipose tiss ue deposition.