Surfactant Protein A and B Gene Polymorphisms and Risk of Respiratory Distress Syndrome in Late-Preterm Neonates

<div><p>Background and Objectives</p><p>Newborns delivered late-preterm (between 34^0/7 and 36^6/7 weeks of gestation) are at increased risk of respiratory distress syndrome (RDS). Polymorphisms within the surfactant protein (SP) A and B gene have been shown to predispose to RDS in preterm neonates. The aim of this study was to investigate whether specific SP-A and/or SP-B genetic variants are also associated with RDS in infants born late-preterm.</p><p>Methods</p><p>This prospective cross-sectional study included 56 late-preterm infants with and 60 without RDS. Specific SP-A1/SP-A2 haplotypes and SP-B Ile131Thr polymorphic alleles were determined in blood specimens using polymerase-chain-reaction and DNA sequencing.</p><p>Results</p><p>The SP-A1 6A⁴ and the SP-A2 1A⁵ haplotypes were significantly overrepresented in newborns with RDS compared to controls (OR 2.86, 95%CI 1.20–6.83 and OR 4.68, 95%CI 1.28–17.1, respectively). The distribution of the SP-B Ile131Thr genotypes was similar between the two late-preterm groups. Overall, the SP-A1 6A⁴ or/and SP-A2 1A⁵ haplotype was present in 20 newborns with RDS (35.7%), resulting in a 4.2-fold (1.60–11.0) higher probability of RDS in carriers. Multivariable regression analysis revealed that the effect of SP-A1 6A⁴ and SP-A2 1A⁵ haplotypes was preserved when adjusting for known risk or protective factors, such as male gender, smaller gestational age, smaller weight, complications of pregnancy, and administration of antenatal corticosteroids.</p><p>Conclusions</p><p>Specific SP-A genetic variants may influence the susceptibility to RDS in late-preterm infants, independently of the effect of other perinatal factors.</p></div

Distribution of SP-A1 and SP-A2 haplotypes in the two late-preterm study groups.

<p>Distribution of SP-A1 and SP-A2 haplotypes in the two late-preterm study groups.</p

Associations between SP-A1 and SP-A2 haplotypes and RDS.

<p>Associations between SP-A1 and SP-A2 haplotypes and RDS.</p

Combined effect of selected perinatal factors and SP-A1 6A⁴ and SP-A2 1A⁵ haplotypes on the probability for RDS.

<p>Combined effect of selected perinatal factors and SP-A1 6A⁴ and SP-A2 1A⁵ haplotypes on the probability for RDS.</p

Characteristics of the study groups.

<p>Characteristics of the study groups.</p

Associations between SP-B Ile131Thr genotypes and RDS.

<p>Associations between SP-B Ile131Thr genotypes and RDS.</p

Additional file 1 of Cerebral oximetry monitoring versus usual care for extremely preterm infants: a study protocol for the 2-year follow-up of the SafeBoosC-III randomised clinical trial

Additional file 1