How coronary heart disease is inherited
In 2000, BHF Professors Stephen Ball and Sir Nilesh Samani (now our Medical Director) launched the Family Heart Study, which we funded in partnership with the Medical Research Council. They collected blood samples from over 4,000 siblings in around 2,000 families with a history of coronary artery disease across the UK. They found that no single gene was responsible for passing heart disease down through families. Instead, tiny DNA variations, known as polymorphisms, in more than one region of DNA alters a person’s risk of developing it.
The study was extended to include more than 190,000 people through an international research collaboration led by Professor Nilesh Samani with colleagues in the Europe and the US. This study identified both genes and new polymorphisms that have an effect on the risk of developing coronary heart disease. Most of them have very little effect on their own, but families that carry lots of these DNA variations tend to be burdened with premature heart attacks.
Finding the key culprits?
In 2007, within weeks of each other, the team behind the Family Heart Study database and three other teams from around the world announced they had made the same discovery. They found a polymorphism, known as chr9p21, on chromosome 9, that nearly doubled the risk of premature coronary heart disease in some people.
2009 was another year of big discovery. Based on data from the Family Heart Study and some additional data, BHF Professor Hugh Watkins showed that people with high blood levels of a cholesterol-containing molecule called lipoprotein (a) are at much greater risk of premature coronary heart disease. This finding combined with other BHF-funded research evidence revealed levels of lipoprotein (a) to be a risk factor for heart disease.
Searching for the next breakthrough
We’ve funded pioneering large scale DNA analysis studies and supported UK research leaders to collaborate across the world. We now have a wealth of information about the DNA variations that make some families much more vulnerable to heart and circulatory diseases.
Many DNA polymorphisms occur in genes that help to regulate well known risk factors, such as cholesterol or blood pressure. But polymorphisms are also found in genes that have never before been linked to heart disease; and some occur in DNA regions that we know very little about. This opens up a wealth of new possibilities for preventing or treating heart disease.
But finding the DNA changes is just the start. Now we’re funding research to understand how DNA changes raise the risk of heart disease. By revealing exactly how each polymorphism affects our bodies, we can strive to find ways to personalise the advice, prevention and treatment that every family receives.