Actress Angelina Jolie announced in a 2013 New York Times editorial that she had both breasts removed. The reason: a heightened risk of breast cancer due to a mutation of the BRCA gene. Two weeks after Jolie’s editorial hit the newsprint, genetic testing among women for the BRCA mutation jumped by 64 percent.
Genes help determine your risk for a number of conditions. “We realize genes play a role in most of our health and development,” says Carla Bell, a certified genetic counselor with Wesley Medical Center in Wichita, Kansas.
“We may not know all the pieces but we know genes are a big piece. We’re still learning what these genes are and how they interact with each other and other environmental factors.”
But how much do genes really control your destiny? And what can you do about genetic risks?
What genes do
Humans have between 20,000 and 25,000 genes. “Genes are blueprints for proteins,” says Bell. “Proteins interact with other proteins and form larger structures, which interact with each other,” from cells to tissues to organs.
Problems may arise with mutations, alterations in genes. Mutations can be inherited from your parents, or something in your environment can cause it. A mutation in the BRCA gene that increases the risk of breast cancer is one such mutation that you get from your parents, while mutations from smoking are examples of how your environment can affect your genes.
Genes, interactions and conditions
Genes interact with each other and the environment a number of ways researchers don’t yet fully understand. “A lot of genes seem to combine with each other and raise or lower risks by a small amount,” says Bell.
Additionally, there is evidence that some genes have a hand in the risk factors of a variety of conditions. For example, people with a family history of fibromyalgia have an eight times higher risk of developing the disease themselves, and there is some evidence that those genetic factors are also tied to irritable bowel syndrome, depression and migraine headaches.
Health conditions with a genetic component
While some diseases like sickle cell disease and cystic fibrosis are caused by mutations of just one gene, most others have both genetic and lifestyle components.
“For many chronic conditions we see commonly, they’re multifactorial,” says Bell. “That means they’re caused by multiple genes, environmental factors and genetic interactions. It’s about how genes are turned on and off. Some of that is programmed in the womb and some comes from the environment.”
Nearly all diseases have a genetic component of some sort, either inherited or environmental. Some of the more common conditions caused at least in part by genetic changes include:
- Asthma
- Cancer
- Coronary heart disease
- Diabetes
- High blood pressure
- Stroke
- Down syndrome
- High cholesterol
- Obesity
- Addiction
- Autism
- Bipolar disorder
- Depression
- ADHD
- Schizophrenia
What you can do about a genetic risk
“Genetic testing can be vital,” says Bell.There are many ways to test genes, such as screening for birth defects, looking for a family history of conditions, or testing a biopsy to see what mutations it has. Some forms of lung cancer have a genetic mutation where cells can’t stop dividing, and targeted therapy can flip that genetic switch off. Newborn babies are screened for about 30 genetic diseases soon after birth, according to Bell. “We know if we can catch some of these diseases before they’re symptomatic we can treat them,” she says.
And while you can’t control which genes you inherit, there are other risk factors you can control. “These genetic tests can be important for people to take something seriously,” Bell says. “If you have a predisposal for a heart condition, that might lead you to watch your cholesterol and exercise more frequently.”
