Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant vascular dysplasia leading to telangiectases and arteriovenous malformations of skin, mucosa, and viscera. Epistaxis and gastrointestinal bleeding are frequent complications of mucosal involvement. Visceral involvement includes that of the lung, liver, and brain. The most frequent form of hereditary hemorrhagic telangiectasia maps to the long arm of chromosome 9.
Genetic Heterogeneity of Hereditary Hemorrhagic Telangiectasia
See also HHT2 (600376), caused by mutation in the ALK1 gene (ACVRL1; 601284) on chromosome 12q13; HHT4 (610655), mapped to chromosome 7p14; and HHT5 (615506), caused by mutation in the GDF2 gene (605120) on chromosome 10q11.
A locus formerly designated HHT3 and mapped to chromosome 5 was found to be in error; see HISTORY. Affected members of the family in which the HHT3 locus was mapped were found to have a mutation in ENG (see MOLECULAR GENETICS) and have been included in HHT1.
See also juvenile polyposis/HHT syndrome (175050), caused by mutation in the SMAD4 gene (600993). [from
OMIM]