[Advances in genome-wide association studies on essential hypertension]

Since the first genome-wide association study was reported in 2007, hypertension has attracted numerous studies to identify its genetic basis. The first part of the current review summarizes the genetic loci associated with blood pressure/ hypertension identified by genome-wide association studies (GWAS) from January 2007 to September 2011, by race and chromosomal location. In the second part, we stress several important points in GWAS methodology, for example, selecting high-quality phenotypes and using multi-stage study design to increase the power studies to identify loci with minor effect. For statistical analysis, besides multiple testing correction and replication of the GWAS that have been introduced in previous reviews, computer-based genotype imputation has been described for its advantages in compensating GWAS genotyping failures. Although GWAS identifies many unknown genetic variants and improves our understanding for the pathogenesis of hypertension, the loci related to blood pressure / hypertension are common sequence variations with minor effect. The association studies are difficult to be replicated in different populations. Further studies are expected including extensive functional studies and fine mapping using advanced techniques, such as whole genome exon sequencing and pathway analysis, as well as epigenetic study to elucidate the etiology of human essential hypertension.