Association between gene mutations of surfactant protein C gene exon II and neonatal respiratory distress syndrome

Objective To investigate association between gene mutations of surfactant protein C(SP-C) exonⅡ and neonatal respiratory distress syndrome(NRDS). Methods From January 2013 to December 2014 in Neonatal Intensive Care Unit of Bayi Children's Hospital Affiliated to Beijing Military General Hospital, a total of 90 cases with NRDS were selected as NRDS group, and they were grouped into 3 subgroups, 30 cases in each subgroup.Clinical data were collected by observation figures.A total of 90 cases without NRDS as control group were matched with NRDS group as for the gestational age (GA), gender and birth weight(BW). The study samples were from the clinically diagnosed venous sampling 1 mL, and genomic DNA was extracted with routine technique.After the polymerase chain reaction (PCR) amplification of sequencing was performed.Chromas software and Vector NTI Advanc software were used for analysis, the results were compared with the normal SP-C sequence of GenBank. Results Heterozygous missense mutations included c. 115G>T and c. 139G>C existed in exon Ⅱ of SP-C gene, which changed protein sequence .GT genotype frequency(0.067) of c. 115G>T mutation in NRDS group was higher than that(0) in control group (χ2=7.283, P T gene mutations in patients with NRDS, Ⅲ-Ⅳ grade chest changed and mortality was higher than that of control group.GC genotype frequency(0.067) of c. 139G>C mutation in NRDS group was higher than that(0) in control group (χ2=6.207, P<0.05). Among NRDS group, 64 cases of cesarean section patients, GC genotype frequencies were lower than GG genotype frequency (χ2=9.276, P<0.01), 55 cases of patients needed 3-4 PS pulmonary surfactant treatment, GC genotype frequencies were lower than GG genotype frequency (χ2=5.343, P<0.05). Conclusions Two heterozygous mutations were located in SP-C gene of exon Ⅱ in Chinese Han population of this study.These mutations have never been reported before.c.115G>T of SP-C gene mutation is associated with pathogenesis and severity of NRDS and increases the risk of death in NRDS; while c. 139G>C of SP-C gene mutation is associated with pathogenesis of NRDS, but it does not increase the risk of severity and death in NRDS. Key words: Surfactant protein C; Gene mutation; Neonatal respiratory distress syndrome