A heterozygous defect for structurally altered pro-alpha 2 chain of type I procollagen in a mild variant of osteogenesis imperfecta. The altered structure decreases the thermal stability of procollagen and makes it resistant to procollagen N-proteinase.

Sippola 1984 · Sippola M, Kaffe S, Prockop D J · Journal of Biological Chemistry · 1984