Endothelin-1 and endothelial nitric oxide polymorphisms in idiopathic pulmonary arterial hypertension.

Idiopathic Pulmonary arterial hypertension (IPAH) is a debilitating disease associated with very poor prognosis. The disease is characterised by endothelial dysfunction, smooth muscle proliferation and insitu thrombosis in the pulmonary artery, eventually leading to right ventricular failure. Two of the key endothelial mediators implicated in the pathogenesis of IPAH are endothelin-1 (EDN1) and nitric oxide (NO). EDN1 is a potent endogenous vasoconstrictor whereas NO is a vasodilator. In the present study screening of the EDN1 gene (EDN1) and NOS3 polymorphisms was taken up, to evaluate their association with IPAH. A significant association of EDN1 3A/4A polymorphism (+138 A; rs10478694) (OR-3.485; CI-1.254, 9.999; p=0.013) and EDN1 Lys198Asn polymorphism (G/T, rs5370) (OR-3.378, CI-1.104, 10.582; p=0.03) with IPAH was observed. Our results indicate that EDN1 polymorphisms in interaction with other genetic markers may play a significant role in individual's susceptibility to the disease and its clinical progression.