The gene encoding the hydrophobic surfactant protein SP-C is located on 8p and identifies an EcoRI RFLP.

Pulmonary surfactant is composed primarily of phospholipids but also contains three known surfactant-specific proteins. These proteins are important in determining the physical properties of pulmonary surfactant--including its ability to adsorb to an air-liquid interface and its structure--but also appear to influence surfactant metabolism. We have previously assigned two surfactant proteins, SP-A (a 28-36-kDa glycoprotein) and SP-B (an 18-kDa hydrophobic protein), to the short arm of chromosome 10 and to chromosome 2, respectively. We now report that the gene encoding the 5-8 kDa hydrophobic surfactant protein SP-C is located on the short arm of chromosome 8. A cDNA clone encoding the entire protein recognizes a useful EcoRI restriction-site-length polymorphism. Evaluation of congenital syndromes manifesting autosomal abnormalities does not further elucidate the functional role of this protein in promoting normal respiratory physiology.