hereditary hemorrhagic telangiectasia
MIM.187300 9q34.1
Hereditary hemorrhagic telangiectasia (HHT) is a genetic angiodysplasia affecting multiple organs, characterized by cutaneous, mucosal, and visceral vascular anomalies.
Types
hereditary haemorrhagic telangiectasia (HHT)
hereditary haemorrhagic telangiectasia with digestive juvenile polyposis (JHPT)
Synopsis
vascular lesions (26%) (12843319)
- telangiectases
- mucosal telangiectases
- conjunctival telangiectases
- nail bed telangiectases
- finger pad telangiectases
-
arteriovenous malformations (AVM)
- pulmonary arteriovenous malformation (PAVM) (4%) (12843319)
- cerebral arteriovenous malformation (CAVM) (3%) (12843319)
- coronary arteriovenous malformation (9671858)
- celiac arterioveinous malformation
- mesenteric arterioveinous malformation
- hepatic arterioveinous malformation (and cirrhosis)
- cerebral arterioveinous malformation
- spinal arterioveinous malformation
- pulmonary capillary hemangiomatosis (14991548)
- arterial aneurysms
- venous varicosities
hemorrhages
- epistaxis
- subarachnoid hemorrhage
- intracerebral hemorrhage
- digestive hemorrhages
HHT and digestive juvenile polyposis (JHT syndrome) (MIM.175050) (11795766, 9892274, 8165825)
- MADH4 (SMAD4) mutations (MIM.600993) at 18q21.1
Etiology
Locus HHT1: mutation in the gene encoding endoglin (ENG) (MIM.131195) at 9q34.1
Locus HHT2: mutations in the activin receptor-like kinase-1 gene (ACVRLK1) (MIM.601284) at 12q11-q14
Locus HHT3 (localization unknown; gene unknown)
Locus JP-HHT (juvenile polyposis and HHT): MADH4 mutations (MIM.600993) at 18q21.1