Chinese Han Population With Essential Hypertension And Blood Pressure Phenotypes And Human Chromosome 1 And 2q14-23 Linkage Analysis Between 5q32 And Adrb2 Gene Polymorphism Association Study

Background and objectives: Hypertension is a major risk factor for coronary artery disease, stroke, and renal disease. Multiple studies have documented that genetic factors influence the interindividual variations in blood pressure (BP) levels and the development of hypertension. One approach to identify BP/EH genes is through a genome-wide or a positional linkage scan to identify chromosomal regions linked to BP or EH using a family based samples. Another approach is through the studies of candidate genes. This type of study is to examine the association of the polymorphisms and the haplotypes composed of these polymorphisms in certain genes with BP or EH. Two papers published in 2000 and 2001 indicated that human chromosome 5q32 and 2ql4-23 were in linkage with EH in Chinese. These findings were supported by several studies performed in Whites. Another focus of the linkage study tends to be chromosome 1. Studies performed in Taiwan Chinese, Canadians and Mexican Americans suggested that human chromosome 1p was linked to EH or BP levels. Among the genes harbored in all these chromosomal regions, the gene encoding adrenergic receptor β2 (ADRB2) was located in 5q32. Some authors reported an association of the three SNPs in the ADRB2 gene, namely, -47C/T, Arg16/GIy and Gln27/Glu, with EH/BP in several populations, whereas other authors did not. The aim of this study is to replicate the positive linkage of chromosome 1, 2q14-23 and 5q32 with EH/BP in a sample of Chinese hypertensive families. Furthermore, we examined the relationship between the three polymorphisms in the ADRB2 gene and EH/BP, and to elucidate the possible relationship of these regions/loci/polymorphisms with EH in Chinese.Materials and Methods (Linkage Analyses): We performed a genetic analysis on 148 randomly ascertained families containing 328 affected sib pairs. To be eligible for our study, members of the family had to meet the following criteria: (1) Age greater than 15 years; (2) Either of two parents with hypertension; (3) Two or more siblings with hypertension; (4) No evidence of secondary hypertension; and (5) Resting-sitting SBP ≥ 140 mmHg and/or DBP ≥ 90 mmHg on three different occasions. The clinical...