Bleeding in the heritable connective tissue disorders: mechanisms, diagnosis and treatment.

Easy bruising and bleeding are prominent features of some heritable disorders of connective tissue (HDCT), resulting from fragility of capillaries and the perivascular connective tissue rather than clotting or platelet dysfunction. The bleeding tendency is most prominent in the Ehlers-Danlos syndrome (EDS), a heterogeneous group of HDCT sharing clinical manifestations of fragility in skin, ligaments, blood vessels and internal organs. Most EDS-subtypes are caused by mutations in genes encoding fibrillar collagens type I, III or V, or genes encoding enzymes involved in the posttranslational modification of collagens. In the vascular subtype of EDS, caused by defects in type III collagen, fragility of vessel walls can lead to life-threatening bleeding and premature death. Bleeding tendency is also a common feature in other EDS-subtypes, leading to bruising either spontaneously or after minimal trauma. This paper reviews the clinical aspects of bleeding and bruising in different HDCT and covers diagnostic and therapeutic aspects relevant to bleeding in these disorders.