When you go to your family doctor, at some point you’ve probably been asked about your “family history”. Has anyone in your family had this disease or that? Parents, siblings, grandparents? How old were they when it happened?
Your doctor isn’t just being nosy by asking these questions. Many diseases run in families and if someone closely related to you has a certain condition, you might be at higher risk of having it yourself.
This is true for many types of cardiovascular disease (diseases of the heart and blood vessels), including heart attack and stroke. Genes can be passed on through family members that make other family members more likely to develop certain conditions.
About a dozen specific kinds of heart disease are known to be passed down directly from our parents, and researchers have discovered many of the genes responsible for them. These conditions include names like Brugada syndrome, familial dilated cardiomyopathy and long QT syndrome. Many of them involve certain types of damage to or deformities in the heart.
Genetic testing is now available for many of these conditions. However, none of them is common and there’s no reason to be tested for them unless you already know you have a relative with one of them. Still, if you have family members who died suddenly or had a heart attack before the age of 50, try to find out more about the circumstances and give this information to your doctor.
Inherited risk of disease
Most common cardiovascular diseases aren’t inherited directly. Instead, we inherit a tendency to develop them. For example, some families have a history of heart attacks, even though not everyone in the family is affected.
Rather than being directly caused by a specific gene or genes, common cardiovascular diseases – such as angina (chest pain), heart attack, stroke or heart failure – are caused by a number of factors that work together. These factors include a number of genes, other conditions (including high blood pressure and diabetes) and lifestyle choices (such as diet and exercise). In common cardiovascular diseases, the role of individual genes is believed to be minor – especially when compared to important modifiable risk factors such as diet, weight control and physical activity.
Genetic testing is not useful in these situations, partly because so many other factors also play a role and partly because not all the genes involved in causing cardiovascular disease have been identified yet. Instead, your doctor will use your family history of disease along with information about your health and lifestyle to determine your risk level and what should be done about it.
Inherited risk factors
High blood pressure, diabetes and abnormal cholesterol levels can all increase your risk of developing cardiovascular disease. Like many other conditions, these appear to be caused by the actions of several genes working together with lifestyle factors. For the most part, individual genes play minor roles and how they interact is not yet well understood.
At this point genetic testing for risk factors isn’t particularly useful except for specific inherited diseases such as some kinds of cholesterol disorders. However, in general, if other members of your family have high blood pressure, diabetes or abnormal cholesterol levels, you may be at higher risk of having them too.
You can’t do anything about your family history – but you can still act to prevent cardiovascular disease.
Please speak to your healthcare professional before starting any new exercise program.