Lethal perinatal type II osteogenesis imperfecta in a family with a dominantly inherited type I.

The genetic heterogeneity and the difficulty of accurate genetic counseling in some cases of osteogenesis imperfecta (OI) is shown by the present report. All signs characteristic of OI type II were observed in a newborn infant who died immediately after delivery: curved and deformed limbs, multiple bone fractures, enlarged and soft skull. An autosomal recessive mode is usually admitted for OI type II. However, several cases of OI tarda levis (autosomal dominant) are noticed in the maternal family. The possibility of a relationship between these two types of osteogenesis imperfecta in the same family, which might be important for genetic counselling, is discussed.