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).

Inclusion Criteria:

• Newborns with RDS

Exclusion Criteria:

• The infants were excluded if they had any congenital malformation, inherited metabolic abnormalities, intrauterine infection, Rh/Rh incompatibility, pneumonia, pulmonary hypertension, meconium aspiration syndrome, or asphyxia

Newborns with RDS are consecutively recruited for this study from the neonatal intensive care unit (NICU) at Daping Hospital, Third Military Medical University, Chongqing, China, a tertiary care facility. The control blood samples, which are collected from healthy neonatal umbilical cord blood, are obtained from the maternity ward of 80 hospitals in Chongqing and nearby areas.