Association of The Lys198asn Polymorphism of The Endothelin-1 (Edn1) Gene with Congenital Malformations in Newborns
Objective: To evaluate the distribution of alleles and genotypes of the Lys198Asn (rs5370) polymorphism in the EDN1 gene and determine its association with the risk of various pathogenetic variants of congenital anomalies (CAs) in newborns. Materials and Methods: A molecular genetic study was conducted on 123 newborns with CAs (main group) and 110 healthy infants (control group) using PCR. Statistical analysis included the Chi-squared test ($\chi^2$), Odds Ratio (OR), and 95% Confidence Interval (95% CI). Results: Accumulation of the mutant Asn allele was identified in the CA group (23.01% vs. 15.91% in controls), reaching a peak in subgroups with chromosomal pathology (26.47%) and folate-independent CAs (26.19%). The total proportion of Lys/Asn and Asn/Asn carrier genotypes in infants with CAs was 39.82% (vs. 28.18% in controls). A statistically significant association was established between the homozygous Asn/Asn genotype and the risk of CAs with chromosomal pathology (17.65% vs. 3.64% in controls; OR = 5.7; 95% CI: 1.34–24.09). For folate-independent CAs, the Asn/Asn genotype increased the risk by 2.8 times (OR = 2.8; 95% CI: 0,51–15,27). Receiver operating characteristic analysis revealed that the Lys/Asn genotype possesses balanced predictive value for primary screening (AUC = 0.55; OR = 1.56), while the Asn/Asn genotype demonstrates high specificity (SP = 0.96). Conclusions: The Lys198Asn polymorphism of the EDN1 gene is associated with an increased risk of congenital anomalies in newborns, exerting its strongest effect in cases with chromosomal aberrations and folate-independent CAs. The Asn/Asn genotype serves as a highly specific molecular biomarker for stratifying high reproductive risk groups.