Cerebral Hemorrhage Risk in Hereditary Hemorrhagic Telangiectasia

This study is one of the three projects of an NIH Rare Disease Clinical Research Consortium. A "consortium" is a group of centres sharing information and resources to perform research. The consortium research focuses on brain blood vessel malformations in three different rare diseases. The focus of this specific study is on Hemorrhagic Telangiectasia (HHT). HHT is a condition characterized by blood vessel malformations, called telangiectasia and arteriovenous malformations (AVMs), occurring in the brain, nose, lungs, stomach, bowels and liver. Brain AVMs (BAVMs) in HHT are difficult to study because they are rare, affecting approximately 10% of people with HHT. While other types of BAVMs have been studied in depth, studies in the HHT population have been very small. Here, we propose the first large-scale collaboration by joining with 12 HHT Centers of Excellence in North America to perform a large study of risk factors for bleeding from BAVMs, called intracranial hemorrhage (ICH) in HHT patients. The current standard of clinical practice across North America, is to screen all HHT patients for BAVMs with magnetic resonance imaging (MRI). If BAVMs are detected, patients are referred to a multidisciplinary neurovascular team for consideration for treatment. Treatment decisions are made on a case by case basis, balancing risks of complications from the BAVM with risks of therapy, but are limited by the few studies available in HHT. We hope that the knowledge we obtain about the risk factors for intracranial bleeding in these patients from this larger study will help us to improve the care of HHT patients. We plan to study risk factors for rupture of BAVMs, including primarily genetics and imaging characteristics of the BAVMs. Knowledge about risk factors will help in the care and management of HHT patients. This will be achieved through the collection of health information to construct a HHT database, blood sampling and banking (through the National Institute of Neu