Two sibs with an unusual pattern of skeletal malformations resembling osteogenesis imperfecta: a new type of skeletal dysplasia?

We report a 6 year old boy with multiple fractures owing to bilateral, pecu liar, wave-like defects of the tibial corticalis with alternative hyperosto sis and thinning. Furthermore, he had Wormian bones of the skull, dentinoge nesis imperfecta, and a distinct facial phenotype with hypertelorism and pe riorbital fullness. Collagen studies showed normal results. His sister, age d 2 years, showed the same facial phenotype and dental abnormalities as wel l as Wormian bones, but no radiographical abnormalities of the tubular bone s so far. The mother also had dentine abnormalities but no skeletal abnorma lities on x ray This entity is probably the same as that described in a spo radic case by Suarez and Stickler in 1974. In spite of the considerable ove rlap with osteogenesis imperfecta (bone fragility, Wormian bones, and denti nogenesis imperfecta), we believe this disorder to be a different entity, i n particular because of the unique cortical defects, missing osteopenia, an d normal results of collagen studies.