Studies of Hereditary Hemorrhagic Telangiectasia: Screening Methods for Pulmonary Arteriovenous Malformations; Prevalence of Pulmonary and Cerebral Arteriovenous Malformations; Prevalence of Cardiac Valve Abnormalities; and Identification of Modifier Genes

PROTOCOL OUTLINE: Patients with hereditary hemorrhagic telangiectasia (HHT) undergo 5 different screening methods to determine which method is most effective in detecting arteriovenous malformations (AVM). Patients may participate in more than one screening method. In part 1, patients undergo 3 different screening techniques (e.g., pulse oximetry, spiral computed tomography (CT), and contrast echocardiography) to detect pulmonary arteriovenous malformations (PAVM). Patients in part 2 undergo magnetic resonance imaging (MRI) using gadolinium as the contrasting agent for AVM in the brain, known as cerebral arteriovenous malformations (CAVM). For pregnant women, this procedure may only take place if there is clinical evidence that suggests CAVM. In part 3, Doppler ultrasound is used to screen for hepatic arteriovenous malformations (HAVM). The abdomen of each patient is viewed to detect AVM in the liver. Patients in part 4 undergo echocardiograms as the screening method used to determine common heart valve abnormalities. In part 5, blood samples are drawn from patients and analyzed to locate modifier genes as a possibility in determining severity of HHT.