Investigation of endothelin-1 type A receptor gene polymorphism (-231 G > A) in preeclampsia susceptibility

Objective. Preeclampsia is considered as a multifactorial disorder with a genetic predisposition. Alterations in the endothelin-1 (ET-1) system are considered to take part in triggering the vasoconstriction seen in preeclampsia. Methods. In order to investigate the possible association of the -231 G > A polymorphism in the endothelin-1 type A receptor gene (EDNRA), previously shown to be associated with other conditions characterized by vasospasm, we examined 77 Caucasian preeclamptic women and 67 matched controls including normotensive subjects without history of thromboembolic event, abnormalities in blood pressure, proteinuria, edema and preeclampsia. The genotype was assessed by polymerase chain reaction-restriction fragment length polymorphism (PCR-R-FLP) on genomic DNA extracted from blood samples. Case vs. control allele frequencies and genotype distributions were compared. Results. No significant differences were found when considering both genotype (chi(2) = 0.58, p = 0.75) and allelic frequencies (chi(2) = 0.08, p = 0.77). Furthermore, no significant genotype-related difference was found in relation to clinical features, such as gestational age at onset, systolic and diastolic blood pressure, proteinuria on admission and delivery week. Conclusions. No association between the -231 G > A polymorphism in the EDNRA gene and preeclampsia as well as any correlation with the main clinical features of the disorder were found, thus excluding a role for this polymorphism in susceptibility to preeclampsia.