Family history of illness not always caused by genetics

A study, led by Profs Albert Tenesa and Chris Haley, finds that lifestyle can also travel through the family and affect a person's chances of getting ill.

Hand holding a half smoked cigarette

Depression, heart disease, diabetes and more are all conditions which run in families and are often linked to genes. However, the University of Edinburgh led study found that these conditions can also run in families where children have been adopted. It can also be found between married couples.

The researchers believe this could be because families often have similar lifestyles. They might eat the same food or take part in similar types of exercise. Similarly, a shared smoking habit can cause conditions to cluster within families.

This study shows that any family suffering from certain ailments should look at their lifestyle as well as their genes. It also means that genetic tests may only provide a partial answer to the causes of certain conditions.

For example, it was found that genes play an important role in the risk of depression. However, the household environment we share with our family comes a close second in influencing this risk.

This shows that we should not just think "It is in my genes there is nothing I can do about it." Particularly for conditions associated with heart disease, it appears the environment is an impotant factor. Habits prevail between family members and this suggests we should be trying to modify our behaviour.

Prof Chris HaleyMRC Human Genetics Unit, The University of Edinburgh

If you'd like to know more about the study, you can find the 'Nature Genetics' published paper below:

Evaluating the contribution of genetics and familial shared environment to common disease using the UK Biobank