“Oh no -- I’m turning into my mother!” If you’re a woman over 30, chances are you’ve said this at least once. Maybe you spotted a certain expression in the mirror, or maybe you heard yourself saying something you swore you’d never say to your kids.
Not necessarily, says Susan Hahn, MS, a genetic counselor and the assistant director of communications, compliance, and ethics at the University of Miami School of Medicine's Hussman Institute for Human Genomics.
Genes Aren't Everything
“One thing we fear as geneticists is for people to believe that our medical futures are all predetermined by our genes," Hahn says. "We don’t want women thinking, ‘Oh, my mother had breast cancer, so I’m going to get it too.’ People should be empowered, not disabled.”
A few disorders, like Huntington’s disease, are very strongly genetically linked. If one of your parents has the mutated gene that causes this neurodegenerative disease, you have a 50% chance of inheriting that gene. If you do, you will develop Huntington’s 100% of the time.
But most diseases that you might see in your mother (or your father) do not have nearly such a powerful genetic thumbprint. They’re not single-gene disorders, but rather, as scientists are learning, they’re caused by the complex interplay of multiple genes with our environment.
“You may be born with a genetic predisposition to certain disorders, but that doesn’t mean you will absolutely develop them,” Hahn says. “It’s like a loaded gun. The genetic predisposition is the gun, and lifestyle factors can pull the trigger. Some of these things we can control, and some we can’t.”
So if Mom had certain conditions, how likely are you to develop them yourself -- and what can you do to avoid them?
In some families, an elevated risk for breast cancer is inherited along with brown eyes and great-grandma’s silverware. But you might be surprised at how few cases of breast cancer are linked to a family history.
“About 70% of women who develop breast cancer have no one in their family who’s ever had it before, at least that they know of,” says Wendy Chung, MD, who directs the clinical genetics program at Columbia University Medical Center. “We call those ‘sporadic’ cases. The other 30% of women with breast cancer have at least one person in their family who’s had the disease before: a mother, an aunt, a sister.”
As a daughter, your lifetime risk of developing breast cancer goes up nearly twofold if your mother had the disease. Within that group of women, some have an even stronger family history.
“The more relatives you have who’ve had breast cancer, the higher your risk becomes,” Chung says. “And women who inherit certain genetic mutations, such as those on the BRCA1 and BRCA2 genes, may have a lifetime risk of developing breast and/or ovarian cancer of anywhere from 50% to 85%. If you inherit that mutation from your mother, there is a very strong chance that you will go on to develop breast cancer, too.”
You can also inherit a genetic predisposition to breast cancer from your father’s side of the family. “Sometimes people say, ‘Oh, my father’s mother was the one who had breast cancer, so I don’t need to worry,’” Hahn says. “No. It can run right through your dad’s side as well.”
Women who test positive for BRCA mutations usually monitor their breast health very closely, with advanced screening tools like breast MRI, and more and more are choosing prophylactic surgery to remove their breasts and/or ovaries. Doing this can cut their risk of developing cancer to below that of an average woman.
But what if you don’t have a known genetic mutation, just a mom or an aunt or a few female relatives who’ve had breast cancer? Is there anything you can do to minimize your own risk when you’re not even sure if genes are involved?
Yes. “Many factors can dial your risk up or down," Chung says. "There are things you can do.”
- Alcohol. Moderate alcohol intake -- one glass of wine or beer or less, on average, per day -- does not raise your risk of breast cancer. But regularly drinking two or three alcoholic beverages a day does increase that risk --so keep your alcohol intake moderate, at most.
- Hormone replacement therapy. It’s known that hormone replacement therapy after menopause elevates the risk of breast cancer, so women with a family history of the disease might want to be especially cautious about taking HRT.
- Pregnancy. Having your first baby before age 30 may cut your breast cancer risk, as does breastfeeding. The longer you breastfeed, the greater the protection. “You’re not necessarily going to plan your life around these factors, but, for example, since breastfeeding is very healthy anyway, this can be an added incentive to nurse and nurse longer,” Chung says.
- Weight. Maintaining a healthy body weight helps to lower your risk of many cancers, including breast cancer.
You can combine these lifestyle choices with being more vigilant about screening.
“We’re more successful at curing breast cancer the earlier we catch it, so if you have a strong family history, you’re the type of person who should definitely get a mammogram starting at a younger age than usual," Chung says. "Depending on how strongly the disease runs in your family, you might also consider regular breast MRIs.”
A combination of lifestyle choices and enhanced vigilance can help women do their best to ward off almost any disease they might worry about inheriting from their mothers, Chung says.
Osteoporosis isn’t quite as strongly genetically linked as breast cancer can be, but there are family factors that put you at higher risk.
Smaller-framed Asian and Caucasian women are at particular risk for osteoporosis. So if you inherited that body type from your mom, you need to take particular care of your bones.
“If your mom had a hip fracture, or what we call ‘the dwindles’ -- literally shrinking as she gets older -- there are things you can do,” Chung says.
Of course, much of the groundwork for good bone health is laid during the teen and young adult years, when many young women can’t be bothered with worrying about what their skeleton will be like when they’re 50 or 60.
- Making sure you get enough calcium and vitamin D, either through diet or supplements. (Being cautious about too much sunlight is important to avoid skin cancer, but just 15-20 minutes of direct sunlight a day in total can give you most of the vitamin D you need.)
- Avoiding smoking.
- Getting regular weight-bearing exercise.
- If you are at particularly high risk, your doctor may recommend prescription drugs, which can both treat and prevent osteoporosis, in addition to the lifestyle measures listed above.
Baseline bone density scans are recommended for all women aged 65 and older and those of menopausal age with risk factors, but if your mother, grandmother, great-aunt, and other relatives all had osteoporosis, especially if it was severe, Chung advises talking to your doctor about starting bone scans at a younger age.
“We all know people who’ve had a hip fracture and it’s turned into much worse,” she says. “That’s what you want to try and prevent. You don’t necessarily have to follow in your mother’s footsteps.”
“There are genetic types that are more frequent with certain conditions. Just because you inherit a susceptible haplotype [gene variant], it doesn’t mean you have a 100% chance of getting thyroid disease or lupus, but it does increase your risk significantly," Chung says. "For some of these disorders, if you inherit a susceptible gene from your mother -- or your father, because men do get these too -- it may boost your risk by anywhere from five- to 20-fold.”
The bad news: There's not much you can do to prevent getting many serious autoimmune conditions like rheumatoid arthritis or lupus.
“The fantasy we all have is that you would be able to somehow have an immune-modulating drug, something that would keep the body from attacking itself,” Chung says. “Theoretically, that’s the goal, but it’s balanced against the fact that such medications are usually not benign and have significant side effects.”
But being aware of your added risk does allow you to be vigilant and begin treating these conditions in their earliest stages -- which can make an enormous difference in terms of how fast and how far the disease progresses.
“For example, the big problem with rheumatoid arthritis is that it’s literally destroying the joints. Once they’re destroyed, it’s hard to go back and fix them,” Chung says. “If you get the inflammation under control at a very early stage, it can help to preserve the bone structure and function for as long as possible. If you know you’re at risk, you can watch for early signs and symptoms.”
“This is a very subtle disorder, but it’s easily screened and easily treated,” Chung says. “You can feel run down, depressed, and be gaining weight, and not realize it’s your thyroid. But if you know that your mother and your grandmother were hypothyroid, you can recognize these symptoms and be ‘miraculously cured’ with thyroid medication, rather than being miserable for months or years without knowing what’s wrong.”
As with autoimmune disease, depression is a gender gap condition: It’s more likely that your mother had it than your father. If she did, does that mean you’re more likely to experience clinical depression?
Possibly, but it’s hard to quantify, Chung says. “With mental illness, the more severe the disorder, the more likely it is that there is an underlying genetic basis for it. Schizophrenia and bipolar disorder, developed at a younger age, is much more likely to be inherited. There are specific single genes, for example, that can significantly increase a person’s risk of developing schizophrenia.”
But with more common, less severe psychiatric conditions, like clinical depression, the underlying factors are more complicated. “Genetics are probably involved, but depression also has to do with factors like how you grew up, the environment around you, the people involved in your life in your formative years,” Chung says. “There’s a family contribution to depression, but it’s not just genes, but also what people share in their families in general.”
If you’ve seen your mother, aunt, or sister go through depression, it’s a clue to be vigilant about your own mental health issues, just as with physical conditions like breast cancer and osteoporosis. “If you do start having mild depression or becoming more debilitated, there’s no reason to go through it alone,” Chung says. “We have very good treatments that can help you get on with your life.”
Be Empowered, Not Afraid
No matter what conditions your mom may have had, and no matter what risk they may have passed on to you, nothing is written in stone.
“Use genetic information to empower you, not to debilitate you,” Hahn says. “Don’t say, ‘I’m destined to get diabetes, I might as well eat what I want.’ There are things you can do to lower your chance of getting many diseases, and early detection is important as well. Don’t use your family history as a determining factor; use it as a motivator.”