Hereditary Hemorrhagic Telangiectasia (HHT) in Dentistry: A Literature Review

Abstract

Hereditary Hemorrhagic Telangiectasia (HHT) is an autosomal-dominantly-inherited vascular dysplasia characterized by age-dependant incomplete penetrance and variable expressivity, with clinical manifestations consisting in epistaxis, mucocutaneous telangiectases, gastrointestinal bleeding and arteriovenous malformations (AVMs), which affects approximately ½ million people world-wide. It affects males and females of all racial and ethnic groups. Up to 1/3 of HHT patients have multiple organ involvement, which can be disabling and/or life threatening. HHT can be treated successfully if correctly diagnosed. Morbidity of HHT is often due to complications of AVMs, such as stroke or haemorrhage, also known to occur in children. Many authors have reported successful new therapeutical options for AVMs, which have resulted in a significant decrease of life-threatening complications and HHT morbidity. Since early diagnosis permits an appropriate care of affected subjects, a very sensitive mutation screening technique is required to identify the mutation carriers among all at-risk individuals belonging to HHT-families. There may be one or more genes that cause HHT but, if so, they are quite rare. Currently, scientists are trying to better understand exactly how the abnormal gene can interfere with normal blood vessel formation and promote the phenotype of HHT, so that better treatments for the symptoms of HHT can be developed.