Hereditary Hemorrhagic Telangiectasia (Osler-Weber-Rendu Disease)

Synonyms

Osler-Weber-Rendu syndrome

Definition

It is a familial syndrome characterized by the presence of multiple superficial telangiectasias (skin, lips, oral cavity, fingers, nasopharynx, and conjunctiva) combined with arteriovenous malformations (AVMs) of the internal organs (lung, brain, gastrointestinal tract, liver, and spinal cord) (Goldberg and Bullock 1990; Ferri et al. 2014).

Etiology

HHT is a rare autosomal dominant disorder that leads to dysplasia of blood vessels throughout the body (Goldberg and Bullock 1990; Ferri et al. 2014). Gene mutations lead to endothelial cell loss and weakness in the perivascular connective tissue with subsequent dilatation of the vessel wall. Most commonly, HHT patients have mutations in the endoglin and activin A receptor-like kinase 1 (ALK1) genes. Endoglin, SMAD4, and ALK1 are involved in cell surface signaling via the transforming growth factor-β (TGF-β) receptor complex (Morelli 2011; Rinaldi et al. 2011).

Type	Gene with associated mutation