Endothelin-1 gene and endothelin receptor A gene polymorphisms in severe pulmonary hypertension associated with rheumatic mitral valve disease

Gender Differences in Genotypic Distribution of Endothelin-1 Gene and Endothelin receptor A gene in Pulmonary Hypertension associated with Rheumatic Mitral Valve Disease

Introduction

The female gender is a risk factor for idiopathic pulmonary arterial hypertension. However, it is unknown whether females with rheumatic mitral valve disease are more predisposed to develop pulmonary hypertension compared to males.

Aim

We aimed to investigate whether there was a difference in genotypic distribution of endothelin-1 (ET-1) and endothelin receptor A (ET_A) genes between female and male patients of pulmonary hypertension associated with rheumatic mitral valve disease (PH-MVD).

Methods

We compared prevalence of ET-1 gene (Lys198Asn) and ET_A gene (His323His) polymorphisms according to gender in 123 PH-MVD subjects and 123 healthy controls.

Results

The presence of mutant Asn/Asn and either mutant Asn/Asn or heterozygous Lys/Asn genotypes of Lys198Asn polymorphism when compared to Lys/Lys in females showed significant association with higher risk (odds ratio [OR] 4.5; p =0.007 and OR 2.39; p =0.02, respectively). The presence of heterozygous C/T and either mutant T/T or heterozygous C/T genotypes of His323His polymorphism when compared to wild C/C genotype in females showed a significant association with higher risk (OR 1.96; p =0.047 and OR 2.26; p =0.01, respectively). No significant difference was seen in genotypic frequencies in males between PH-MVD subjects and controls. Logistic regression analysis showed that mutant genotype Asn/Asn (p =0.007) and heterozygous genotype Lys/Asn of Lys198Asn polymorphism (p =0.018) were independent predictors of development of PH in females.

Conclusions

ET-1 and ET_A gene polymorphisms were more prevalent in females than males in PH-MVD signifying that females with rheumatic heart disease may be more susceptible to develop PH.