<unk> , also called acroosteolysis with osteoporosis and changes in skull and mandible, arthrodentoosteodysplasia and<unk>  syndrome, is an extremely rare autosomal dominant congenital disorder of the connective tissue characterized by severe and excessive bone resorption leading to osteoporosis and a wide range of other possible symptoms. Mutations in the NOTCH2 gene, identified in 2011, cause HCS. HCS is so rare that only about 50 cases have been reported worldwide since the discovery of the syndrome in 1948
Hajdu–Cheney syndrome
Cleidocranial dysostosis
MEDNIK syndrome
ATR-16 syndrome
Aarskog–Scott syndrome
Treacher Collins syndrome
GRACILE syndrome
Heimler syndrome