 Lung fluid absorption disorders are largely mediated by transepithelial Na reabsorption through alpha epithelial sodium channels α-ENaCs in alveolar epithelial cells. Increasing evidence has demonstrated that these lung disorders might be an important cause of neonatal respiratory distress syndrome NRDS by influencing gas exchange or surfactant function, particularly in near-term and term infants. The SCNN1A gene, which encodes the α-ENaC, might predispose infants to NRDS. To explore whether the single-nucleotide polymorphisms SNPs of SCNN1A are associated with NRDS, we conducted a case-control study to investigate the NRDS-associated loci in Han Chinese infants. Seven target SNPs were selected from the SCNN1A gene and were genotyped using the improved multiplex ligase detection reaction iMLDR. 