[A cross-racial analysis on the susceptible gene polymorphisms of salt-sensitive hypertension]

To compare the genetic distributions of salt-sensitivity of four ethnic populations in Hapmap database.

The frequencies data (395 subjects) of salt-sensitivity polymorphisms (AGT/M235T, ACE/ID, CYP11B2/C-344T, ADDI/Gly460Trp, GNB3/C825 and CYP3A5/A6986G)of Utah residents with ancestry from northern and western Europe (CEU), Han Chinese in Beijing (CHB), Japanese in Tokyo (JPT) and Yoruba mother-father-child trios in Ibadan, Nigeria (YRI) were obtained from International HapMap Project. The good-fit χ(2) test was performed to test whether the frequencies of each genotype reached Hardy-Weinberg equilibrium. The differences of the genotype and allele distribution and trend analysis were detected via χ(2) test. Furthermore, multiple comparisons between two populations were analyzed by Lancaster's partition of chi-squares.

There were significant differences of each genotype distribution among four ethnic populations (P < 0.05). The distribution of genotype frequencies and susceptible allele frequencies of salt sensitive candidate genes were similar between CHB and JPT. Excepted for GNB3/825T allele (38.8% vs.34.4%, P = 0.521), susceptible allele frequencies in AGT/235T (79.2% vs. 41.2%, P < 0.001), ACE/I (56.5% vs. 43.5%, P < 0.001), CYP11B2/-344T (74.1% vs. 56.7%, P = 0.001), ADDI/460Trp (51.8% vs. 20.4%, P < 0.001) and CYP3A5/A6986 (30.1% vs. 3.6%, P < 0.001) were significantly higher in CHB than in CEU. There distribution of ADDI/460Trp allele was significant lower in YRI (4%) than in CHB (51.8%, P < 0.001). However frequencies of AGT/235T, CYP11B2/-334T, GNB3/825T and CYP3A5/6986A in CHB were significantly lower than those in YRI (P < 0.05). Trend analyses showed significantly increased trend in AGT/235T (41.2% < 79.2% < 92.0%, P < 0.001), CYP11B2/-334T (56.7% < 74.1% < 84.8%, P < 0.001) and CYP3A5/6986A (3.6% < 30.1% < 84.5%, P < 0.001) in CEU, CHB and YRI.

There are significant discrepancy of salt-sensitivity variant distributions among four ethnic populations in Hapmap database. The frequencies of the susceptible polymorphisms related to salt-sensitivity in Beijing Han population was similar with JPT, higher than in CEU but lower than in YRI, suggesting high salt-sensitive and risk for hypertension in Beijing Han population. Prevention and individual therapy for high-risk population will help to reduce the prevalence of salt-sensitive hypertension and cardiovascular diseases.