Variations In Intron4of Surfactant Protein B In Infants With Bronchopulmonary Dysplasia

Objective To explore the variations of surfactant protein B (SP-B) intron4ininfants with bronchopulmonary dysplasia (BPD).Methods Forty five infants with bronchopulmonary dysplasia (BPD group)and other ninety nine infants without lung diseases (control group) admitted intoTongji Hospital, Tongji Medical College, Huazhong University of Science andTechnology from July2008to July2011were selected into this study. Genotyping forfragment length polymorphism of SP-B intron4(i4) was performed usingpolymerase chain reaction (PCR), agarose gel electrophoresis, cloning and sequencingmethods in the two groups. Differences of allele frequencies (invariant allele andvariant allele) and genotype frequencies (invariant genotype and variant genotype)between BPD group and control group were analyzed. The gestation age and birthweigh between the two groups were compared with Independent-Samples T Test. Thegender composition and the differences of allele or genotype frequencies between thetwo groups were compared with Chi-square Test.Results Allele frequencies in BPD group and control group, invariant allelefrequencies were respectively83.3%(75/90) and92.0%(182/198), variant allelefrequencies were respectively16.7%(15/90, including8insertion alleles and7deletion alleles) and8%(16/198, including8insertion alleles and8deletion alleles),there were statistical significances between the two groups (x2=4.75, P<0.05). InBPD group, invariant genotypes were32cases (71.1%,32/45)，variant genotypeswere13cases (28.9%,13/45, including7cases insertions and6cases deletions); incontrol group, invariant genotypes were85cases (85.8%,85/99)，variant genotypeswere14cases (14.2%，14/99,6insertions and8deletions)，there were statistical significances between the two groups (χ~2=4.42, P<0.05).Conclusions Variations of SP-B intron4are higher in BPD infants; thevariations of SP-B intron4may be associated with BPD.