Cardiovascular
Also called HHT, Osler-Weber-Rendu Syndrome, Osler Syndrome
Hereditary Hemorrhagic Telangiectasia results from mutations in genes regulating blood vessel integrity, most commonly endoglin (ENG gene, HHT1) or activin receptor-like kinase 1 (ALK1, HHT2 gene), and less commonly other genes. These mutations impair transforming growth factor-beta (TGF-β) signaling, crucial for proper blood vessel development and maintenance.
Hereditary Hemorrhagic Telangiectasia can manifest at any age from childhood onward, with most cases recognized in childhood to early adulthood. It affects males and females equally. The disease occurs across all racial and ethnic groups. It follows an autosomal dominant inheritance pattern, with 75-80% of affected individuals having an affected parent. About 20% represent de novo mutations. Penetrance is nearly complete, though severity varies considerably even within families.
Clinical trials for Hereditary Hemorrhagic Telangiectasia focus on new medical therapies targeting angiogenesis, including topical and systemic approaches to reduce bleeding frequency and severity. Bevacizumab and other antiangiogenic agents are being investigated. Trials examine bevacizumab nasal spray, thalidomide, lenalidomide, and other agents. Management emphasizes screening for and monitoring internal malformations, particularly pulmonary arteriovenous malformations. Patients should consult with a specialist familiar with HHT and undergo appropriate vascular imaging.