Hajdu-Cheney Syndrome, also known as acroosteolysis with osteoporosis and changes in skull and mandible, is related to meningocele and heart septal defect. An important gene associated with Hajdu-Cheney Syndrome is NOTCH2 (Notch Receptor 2), and among its related pathways/superpathways are Gene expression (Transcription) and Infectious disease. Affiliated tissues include bone and kidney, and related phenotypes are osteopenia and skeletal dysplasia