Single nucleotide polymorphism in 5'-flanking region reduces transcription of surfactant protein B gene in H441 cells.

Surfactant protein (SP)-B is expressed in a cell-specific manner and is essential for surfactant function and survival. Abnormal surfactant function occurs in humans and genetically engineered mice with SP-B levels well below 50% of normal. SP-B mRNA levels vary in fetal lung explants among individuals, possibly due to genetic variety.