Genome-wide association studies of human growth traits.

Despite the high heritability of human growth traits, until recently little was known about the underlying genes and genetic variants which explain normal variation of growth. In the past few years, genome-wide association studies have successfully identified hundreds of genetic variants that are associated with human growth traits. These variants have implicated many novel genes in the regulation of birthweight and pubertal timing through to final adult height, and are providing new insights into the biology of growth. For example, 180 genetic loci have been robustly shown to influence variation in final adult height. Despite this success, the effect sizes of these variants are small and, even in combination, have left the majority of heritable genetic variation of growth traits unexplained. In this review, I discuss the successes of the genome-wide association approach and some of the novel insights into the biology of growth that have come from these studies. I will also discuss what these studies have not told us and what the future holds for genetic studies of human growth.