Association of epithelial sodium channel β-subunit common polymorphism with essential hypertension

Abstract

Objective To investigate the relationship between common polymorphisms in the C-terminus of SCNN1B gene encoding the β- subunit of epithelial sodium channel (ENaC) and essential hypertension (EH) in Beijing Chinese hypertensive families. Methods A total of 433 subjects from 108 essential hypertension families were recruited. They were divided into three groups: EH probands (n=229), first- and second-degree relatives (without EH) of probands (n=118) and spouses (without EH) (n=86). Biochemical indicators, Sv1+ Rv5 of ECG and systematic screening of the C-terminus of SCNN1B were performed. Results rs3743966 and rs34618783 satisfied minor allele frequency≥5% were found. Compared with the control subjects, hypertensive patients (probands) were observed with a significantly higher frequency of AA genotype of rs3743966 (55.5% vs. 44.9% and 32.6%, χ2=13.768, P<0.01) and a significantly lower frequency of TT genotype (9.6% vs. 15.3% and 38.3%, χ2=37.205, P<0.01). There were no differences in terms of rs34618783 genotype frequencies among the three groups. Homozygotes for the rarer T allele had on average a 15.69 mmHg lower SBP and a 9.14 mmHg lower DBP than homozygotes for the common A allele (both P<0.01). In multivariable regression analyses, TT genotype of rs3743966 was found to be an independent protective factor of hypertension (OR: 0.239, 95%CI: 0.117-0.489, P<0.001). TT genotype of rs3743966 may be an independent protective factor of hypertension in Beijing Chinese hypertensive families. Key words: Epithelial sodium channel; Gene; Single nucleotide polymorphism; Essential hypertension