Hajdu-Cheney syndrome (HCS) is a rare, heritable disorder of connective tissue; only about 50 cases have been reported in the medical literature. The breakdown of bone (osteolysis), especially the outermost bones of the fingers and toes (acroosteolysis), is a major characteristic of HCS.
In addition, patients with HCS frequently have skull deformities, short stature, joint laxity, reduction of bone mass (osteoporosis) and other signs. Most affected individuals have normal mental development but a small proportion show mild mental retardation.
Although the majority of cases are of unknown cause, the presence of multiple cases in one family suggests that autosomal dominant genetic transmission may be possible.