Could you be missing a secret illness?

Knowing your history could help the future of your family’s health

- DR PHILIPPA KAYE

When you see a doctor, have you noticed they often ask about family history – whether or not your parents, siblings or children, have or had a particular illness? This is because many conditions seem to run in families, so having a family member with a history of a particular condition may increase your risk of having the same.

The nature-versus-nurture debate rages on. It may never truly be answered until we understand more about genetics and epigenetics, which is how the environment we live in affects our genes. Some of the reasons why diseases seem to run in families may be solely related to genetics, but others may also have lifestyle or environmental factors.

Some conditions are related to a single gene mutation, which can be passed down between family members, such as sickle cell anaemia and sickle cell trait. Others, such as type 1 diabetes, run in families but may involve multiple genes.

Your doctor will often be interested in your family history of conditions, such as cancers, heart disease, stroke, dementia, types 1 and 2 diabetes and autoimmune conditions. Depending on your answers they may ask other questions, including the age at which the person was diagnosed or if there were other factors, such as if they smoked.

For example, the chances of there being a genetic component which could be passed on to you if you had a parent who smoked heavily all their life and had a heart attack in their 80s may be different from a parent who didn’t smoke and had a heart attack in their 40s. Or having one parent who had breast cancer in their 70s, versus having multiple people in the family with breast cancer in their 30s and 40s.