The coding sequence for the human 18,000-dalton hydrophobic pulmonary surfactant protein is located on chromosome 2 and identifies a restriction fragment length polymorphism.

The 18-kd hydrophobic pulmonary surfactant protein (PSP-B) is a developmentally regulated protein which is important for normal lung function. A complementary DNA probe for 221 NH2 terminal amino acids of PSP-B was used to determine the chromosomal location of this gene and identify a restriction fragment length polymorphism (RFLP). Southern blot hybridization to genomic DNA isolated from a panel of human-CHO somatic cell hybrids unambiguously maps this gene to chromosome 2. Human DNA cut with BamHI yields a RFLP with variable bands at 2.8 and 2.6 kb. Since there is a relative lack of polymorphic markers for chromosome 2, this sequence may be useful in linkage analysis.