Association between surfactant protein B gene polymorphisms and susceptibility to bronchopulmonary dysplasia in preterm infant

Objective To investigate the distribution of surfactant protein B(SP-B) gene single nucleotide polymorphisms and to study the association between the SP-B gene polymorphisms and bronchopulmonary dysplasia(BPD) in preterm infant. Methods Forty-two preterm infants with BPD and 68 preterm infants without BPD(control group) were selected.Polymerase chain reaction with restriction fragment length polymorphism was used to establish the genotype and allele frequencies of the SP-B-18A/C, SP-B 1580C/T, SP-B 8714G/C single nucleotide the polymorphisms, and then the association between the polymorphisms and BPD was analyzed. Results The frequencies of genotype CC, AC, AA of SP-B-18A/C in BPD group and control group were 35.7%, 52.4%, 11.9% and 32.3%, 47.7%, 20.0%, respectively.The frequencies of genotype CC, GC, GG of SP-B 8714G/C in BPD group and the control group were 26.2%, 54.8%, 19.0% and 27.7%, 58.5%, 13.8%, respectively.The frequencies of genotype CC, CT, TT of SP-B 1580C/T in BPD group and control group were 66.7%, 26.2%, 7.1% and 40.0%, 47.7%, 12.3%, respectively.The frequencies of allele C and allele A of SP-B-18A/C in BPD group and control group were 61.9%, 38.1% and 56.2%, 43.8%, respectively.The frequencies of allele G and allele C of SP-B 8714G/C in BPD group and control group were 53.6%, 46.8% and 56.9%, 43.1%, respectively.The frequencies of allele C and allele T of SP-B 1580C/T in BPD group and control group were 79.8%, 20.2% and 63.8%, 36.2%, respectively.SP-B-18A/C, SP-B 1580C/T, SP-B 8714G/C were found to be polymorphic.The frequencies of genotype CC of SP-B 1580C/T in BPD group were significantly higher than those in the controls(χ2=7.26, P<0.05). The frequencies of allele C of SP-B 1580C/T were also statistically different between BPD group and control group(χ2=6.17, P<0.05). The C allele increased the risk of BPD(OR=2.23, 95%CI: 1.18-4.24). There was no significant difference between the 2 groups in the frequencies of genotype and allele of SP-B-18A/C and SP-B 8714G/C. Conclusions SP-B 1580C/T polymorphism has association with the etiology of BPD and may serve as the susceptibility gene for BPD, the C allele increase the risk of BPD.SP-B-18A/C and SP-B 8714G/C do not have association with the etiology of BPD. Key words: Bronchopulmonary dysplasia; Surfactant protein B; Single nucleotide polymorphisms; Infant, preterm