Summary of human linkage and association studies

It is now widely accepted that genes play a significant role in the development of human obesity. The mapping of genes contributing to obesity and to regional fat distribution in humans is based on association and linkage studies. This article presents a review of these studies in humans for phenotypes related to excess body mass or body fat and regional fat distribution. The various obesity phenotypes are first defined followed by a brief description of the linkage and association methods. The early association studies based on red blood cell genetic polymorphisms are reviewed and the studies which have reported significant evidence of linkage and association described. Studies with negative findings are not reviewed. Results of these studies suggest a total of 28 genes or chromosomal regions that may be associated and/or linked with body fat and fat distribution phenotypes in human. With genomewide searches for obesity genes actually under way, together with the 16,000 genes and transcripts included in the recent human gene map, this number is likely to increase rapidly in the next few years.