Biethnic Comparisons of Autosomal Genomic Scan for Loci Linked to Plasma Adiponectin in Populations of Chinese and Japanese Origin

Adiponectin is secreted by adipocytes and is thought to have insulin-sensitizing and antiatherogenic effects. Two previous genome scans for plasma adiponectin have identified different regions for European and Pima Indian populations. We here present multipoint linkage analysis of adiponectin levels using a variance-components model for 1007 siblings (from 360 nuclear families) of Chinese origin and 352 siblings (from 147 nuclear families) of Japanese origin. We found heritability for adiponectin concentrations was 0.70 for Chinese and 0.48 for Japanese. Autosomal genome scan was performed using microsatellite markers span at an interval of approximately 10 cM. Suggestive linkage of adiponectin, after adjusting for age and sex, was found on chromosome 15 at 39 cM (maximal LOD score = 3.19, P = 6.3 x 10(-5)) for Chinese; and on chromosome 18 at 28 cM (maximal LOD score = 2.40, P = 4.4 x 10(-4)) for Japanese. There were tentative loci of weak linkage on chromosomes 3, 18, and 20 in Japanese. We provide novel loci on chromosomes 15, 18, and 20 and confirm a region on chromosome 3 as reported in Pima Indians, which may influence differentially on circulating adiponectin concentrations in Chinese and Japanese populations. Further fine mapping of these regions will help to identify the gene(s) that might affect adiponectin levels.