Real Dictionary

osteogenesis imperfecta in American English
a rare hereditary disorder of connective tissue, characterized by thin, brittle bones and progressive deafness
noun: a rare hereditary disease in which abnormal connective tissue development leads to fragile bones subject to fracture

osteogenesis imperfecta in British English
noun: a hereditary disease caused by a collagen abnormality, causing fragility of the skeleton which results in fractures and deformities