[Analysis of association of SP-C gene polymorphisms with Neonatal respiratory distress syndrome].

Objective: To analyze the association between pulmonary surfactant protein C (SP-C) gene polymorphisms and the risk of Neonatal respiratory distress syndrome (NRDS).

Methods: Clinical data from 168 neonates diagnosed with NRDS (NRDS group) admitted between August 2020 and June 2023 were collected. Additionally, 168 neonates without respiratory distress, born during the same period, were included as the control group. Peripheral venous blood samples (2 mL each) were collected from both groups. PCR-restriction fragment length polymorphism technique was employed to detect the polymorphisms at the SP-C gene loci p.Thr138Asn (rs4715) and p.Ser186Asn (rs1124). Hardy-Weinberg equilibrium tests were conducted for genotyping, and genotypic and allelic frequencies were compared. The association between SP-C gene polymorphisms and NRDS risk was evaluated. Furthermore, genotypic and allelic frequencies at the rs4715 and rs1124 loci were compared among NRDS cases with varying degrees of disease severity. The study was approved by the Medical Ethics Committee of Shangqiu First People's Hospital (Ethics No. 2020-031).

Results: The frequency of the variant allele (A) at the rs4715 locus was significantly higher in the NRDS group compared to the control group (32.14% vs. 24.11%, P = 0.001). The frequency of the variant genotype (AA + AC) was also higher in the NRDS group (47.02% vs. 39.29%, P = 0.043). The frequency of the variant allele (A) at the rs1124 locus was higher in the NRDS group compared to the control group (34.23% vs. 23.51%, P = 0.027), with a higher frequency of the variant genotype (AA + AG) in the NRDS group (49.40% vs. 39.29%, P = 0.019). No significant correlation was observed between the rs4715 polymorphism and the severity of NRDS (P > 0.05). Among NRDS children with grade III severity, the frequency of the variant allele (A) at the rs1124 locus was higher than in grade I and grade II children (47.62% vs. 29.22%, P = 0.020). The frequency of the variant genotype (AA + AG) was also higher in grade III children (64.28% vs. 43.84%, P = 0.040).

Conclusion: SP-C gene polymorphisms are associated with the susceptibility to NRDS. Neonates carrying the AA genotype and the A allele at the rs1124 locus are at a higher risk of severe NRDS. These findings have provided further evidence for early screening, diagnosis, and treatment of NRDS.