<unk>  is a genetic bone disorder. People with<unk>  are born without the proper protein (collagen), or the ability to make it, usually because of a deficiency of Type-I collagen. People with<unk>  either have less collagen than normal or the quality is poorer than normal. As collagen is an important protein in bone structure, this impairment causes those with the condition to have weak or fragile bones.
Osteogenesis imperfecta
Geroderma osteodysplastica
Rhizomelic chondrodysplasia punctata
Acrodysostosis
Gnathodiaphyseal dysplasia
Fox-Fordyce disease
Tyrosinemia
Upington disease