Bicuspid aortic valve or BAV is the most common congenital heart condition and half of all people born with it end up needing open heart surgery. Yet many people don’t even know they have it.
BAV usually has no symptoms until later in life, when it resembles heart failure. People experience symptoms like chest pain or shortness of breath and seek medical help. During hospital tests for these they will find out about the condition they were born with.
Around 1 in 100 people are born with BAV, about the same number born with green eyes. People with BAV only have two segments in their aortic valve, which usually has three. These are more likely to weaken over time leading to illness. It is not clear what causes BAV or if there is any way to identify who will get ill or need surgery because of it.
Dr Radek Debiec is working on solving this mystery.
“We think BAV is genetic, so if we can find the faulty genes that cause it we can identify people especially those who may eventually need surgery, ahead of time.”
Studies to find faulty genes usually compare people with the condition to healthy volunteers or a “standard” copy of DNA. However Radek’s team felt this was limited as it didn’t explain how BAV was inherited. They set up the BRAVE study in 2015 to study entire extended families to identify faulty genes.
“Usually the faulty gene is inherited from one of the parents and by looking at the family tree we can predict who else has it. Also the bigger the family the easier it is to find the gene that causes disease because it should be in all people with the condition, but absent in unaffected relatives.”
The BRAVE study is thought to be the biggest collection of extended families with BAV in the UK, but it hasn’t been an easy journey.
“Members of the family do not usually live in the same house, city or even country. We’ve had to adapt by sending blood samples by courier! We also have to work with many other hospitals to get heart scans of all the family members, and sometimes we have to wait for children to grow older as we can only recruit children over 10 years old. That is why it is important that our study continues long-term; so we can follow these families and be sure we’ve found the right genes.”
Despite the challenges, Radek is keen to go further to understand the genetic causes of BAV.
“The power of any genetic study lies in numbers. A new potential faulty gene discovered in one family needs to be confirmed, so we have to find another family with a defect in the same gene.
“These families are helping us give patients more answers and better ways to prepare. We hope our findings could even help other scientists develop treatment that will reduce these risks in the first place.
“We’re receiving more and more referrals from patients across the entire UK. I am currently applying for Intermediate BHF Clinical Research Fellowship. If successful I will develop a National Recruitment Program to expand this study even further.”
Dr Radek Debiec is an Academic Clinical Fellow at University of Leicester and part of the research team for the BRAVE study.