SFTPA2 and newborn respiratory distress syndrome: Overall, the SP-A1 6A4 or/and SP-A2 1A5 haplotype was present in 20 newborns with RDS (35.7%) and in 7 without RDS (11.7%), resulting in a 4.21-fold (95% CI 1.61–11.0) higher probability of RDS in carriers of these haplotypes (P = 0.003, estimated power 89.9%).