title: Osteopetrosis in two brothers with severe mental retardation.
mesh_terms: D002648:Child; D006801:Humans; D008607:Intellectual Disability / Q000150:complications / Q000235:genetics*; D008297:Male; D010022:Osteopetrosis / Q000150:complications / Q000000981:diagnostic imaging / Q000235:genetics* / Q000473:pathology; D010375:Pedigree; D011859:Radiography