Single-nucleotide polymorphisms (SNPs) in SP-A1 and SP-A2, genes encoding SP-A, have been associated with susceptibility to respiratory distress syndrome, COPD, and pulmonary infections.
Serum SP-A level (n=134) was elevated in acute respiratory distress syndrome and in some cases of drowning, fire and MA fatalities, hyperthermia and chest traumas.
Furthermore, one SP-A2 allele (1A0) shown to associate with low SP-A mRNA levels is found with higher frequency in a subgroup with respiratory distress syndrome.