We all know that traits can get passed down in families. Freckles, curly hair, brown eyes – some shared characteristics between family members are plain to see. However, there are also things that cannot be seen: a faulty gene, a heightened risk of heart disease, or a greater susceptibility to depression.
Knowing the medical history of your family can help to reveal these risks. Here, with some insights from Jonjo Hancock-Fell at Westfield Health, we’ll explore eight of the most common conditions that can run in families, what the likelihood is of them being passed on, and what to do if you know about a condition that is present in your family.
According to Cancer Research UK, between 5-10% of diagnosed cancers are linked to an inherited fault in your genes. Some are more likely than others to be caused by genetic factors, including breast cancer and bowel cancer.
5-10% might seem low, but it is reason enough to be aware of any cancer in your family and consider getting regular tests. If more than one family member on the same side has developed cancer, or you are concerned about your risk, speak to a GP or specialist.
Although genetics cannot solely determine whether you’ll develop diabetes, it does play a big role in both Type 1 and Type 2. In fact, if both parents have diabetes, it can increase the child’s likelihood of getting it by 30% for Type 1 and 75% for Type 2.
If left untreated, diabetes can get progressively worse, and it’s important to get it diagnosed early so you can learn how to manage and live with the disease. This can include lifestyle changes, including a healthy diet, regular exercise and insulin injections.
- Cardiovascular conditions
These are often grouped under the umbrella term ‘Inherited Cardiac Conditions’ (ICC) and can include familial cardiomyopathies, familial arrhythmias, Marfan syndrome, and Sudden Arrhythmic Death Syndrome (SADS). ICCs are caused by a genetic mutation, of which there is a 50% chance of passing it down to your children, even if you never develop an inherited condition yourself.
It can be difficult to diagnose an ICC, but if someone in your family has one, you may be advised to undergo tests such as an ECG or echocardiogram.
- Parkinson’s disease
Research is still discovering the exact causes of Parkinson’s, but genetics is thought to be responsible for about 10-15% of all cases. Some evidence also suggests that environmental factors, such as being exposed to pollution or chemicals, can contribute.
If multiple people in your family have Parkinson’s, then you will be at a heightened risk, but overall, it can be a complex combination of factors. You may carry the gene that causes Parkinson’s but never develop the disease.
- Sickle cell disease
Sickle cell disease affects the haemoglobin found in red blood cells. Cells will develop in an unusual shape, which causes problems, including painful episodes, anaemia, and an increased risk of infections.
This is a recessive condition, meaning that in order to inherit it, both parents must be carriers of the gene. If both parents have the sickle cell trait, there is a 25% chance that their child will have the disease and a 50% chance that they will pass on the trait, according to the Sickle Cell Society.
Many people who have someone in their family affected by dementia worry that they will inherit or pass it on. However, most types of dementia have little or no genetic link. For example, less than one in every 100 cases of Alzheimer's disease is inherited. Some kinds of dementia can be hereditary, although it remains rare and is usually affected by other conditions passed on, such as diabetes or high blood pressure. Rarer kinds, such as frontotemporal dementia (FTD) or Huntington’s disease, can run in families.
- Huntington’s disease
Around 1 in 10,000 people in the UK have Huntington’s disease, a type of dementia caused by a gene defect that damages the brain over time.
If someone in your family has Huntington’s disease, there’s a 50% chance that their children will develop it. It’s very rare to get the disease if there is no history of it in your family.
Though symptoms of the disease can be managed with treatment and support, there is no cure for Huntington’s. If there is a history of it in your family and if you’re planning a pregnancy, it’s advised that you speak to your GP for advice.
- Mental illness
Mental illnesses can be distressing for both the sufferer and their loved ones, and thus it can be a big worry that an illness could be passed on.
While research is ongoing, it’s so far thought that mental illnesses are caused by four main factors: genetics, biology, environment, and psychological factors. Some illnesses are more likely to run in families than others, such as autism, bipolar disorder, ADHD, depression, and schizophrenia. The extent of the link between genetics and mental illness is still largely unknown. However, if you have a close relative, like a parent or sibling, who suffers from a mental illness, then you have a higher risk of getting it yourself.
How to gather your family’s medical history
You’ll be unable to access medical records without consent, but even starting conversations with family members can help. The British Society for Genetic Medicine suggests some questions you can ask:
- Do you have any concerns about any illnesses that seem to run on your or your partner’s side of the family?
- Does anyone have a major physical or mental health problem?
- Has anyone in the family needed hospital treatment for a serious illness?
- How old were they when they were diagnosed?
Questions such as these can help you paint a picture of your family’s medical history. You can also build a pedigree, which is a more systematic approach to building an extensive map of medical history.
What should you do if a condition runs in the family?
Early detection of a disease or condition is one of the main ways you can improve your outcomes. Even for conditions that cannot be cured or treated, knowing early on can allow you to make decisions about your future or make changes that will help you in the long term.
Identifying the exact risk of developing a condition can be difficult, but a specialist or genetic counsellor can help you understand your risk, which you can access through the NHS. If you need surgery and your condition is covered, private medical cover may offer a faster route to treatment.
How to reduce your risk
When it comes to reducing your risk of getting a condition that runs in your family, it can be entirely dependent on the condition. You can’t change your genes, but you can make lifestyle changes that may help. For example, having a healthy diet, staying hydrated, and getting the right amount of exercise can reduce the risk of diabetes or some ICCs.
It can be scary facing the possibility of a genetic condition for you or your children. However, knowing your family’s medical history is the first step in becoming empowered to take control of your health.