OBJECTIVETo detect and analyze the genetic variation in exon 7 of lung surfactant protein B (SP-B), and to investigate the relationship between the genetic variation and the incidence of neonatal respiratory distress syndrome (NRDS) in Han populations in western Inner Mongolia.

METHODSIn the case-control study, 47 Han infants with NRDS were assigned to case group. All the 47 patients had the last three generations of their ancestors reside in western Inner Mongolia. Forty-seven Han newborns without NRDS were assigned to control group. PCR-based gene analysis was used to determine the mutation in exon 7 of SP-B gene and genotype and allele frequencies of the R236C site in exon 7 of SP-B gene.

RESULTSIn Han newborns in western Inner Mongolia, there was no mutation in exon 7 of SP-B gene; two genotypes, CC and CT, were identified in the R236C site in exon 7 of SP-B gene. No TT genotype was found in the two groups. There were no significant differences in the genotype frequency of CC or CT as well as the allele frequency of C or T between the case and control groups (CC: 72% vs 85%, P>0.05; CT: 28% vs 15%, P>0.05; C: 85% vs 93%, P>0.05; T: 15% vs 7%, P>0.05).

CONCLUSIONSThere is no mutation in exon 7 of SP-B gene in Han infants with NRDS in western Inner Mongolia. There is no significant association between the gene polymorphism of the R236C site in exon 7 of SP-B gene and the incidence of NRDS in Han populations in that region.