SFTPA1 and newborn respiratory distress syndrome: The combination of SFTPA2 rs17886395 (SNP1) with (i) SFTPA1 rs4253527 (SNP2) as d1d2, increased risk of RDS (OR 1.69, 95% CI 1.32–2.17, adjusted p = 0.004), and (ii) SFTPA1 rs1059047 (SNP2) as d2 without any epistatic effect from SNP1 was protective (OR 0.43, 95% CI 0.29–0.62, adjusted p = 0.004).