Growing up, I felt like my mother and I couldn’t be any more different. She is orderly and logical, with a knack for simply doing the next thing that needs to be done. She has strong convictions about what’s right and wrong. On the other hand, I have never been known as neat or organized. I tend to spend more time dreaming, and, although I have strong moral convictions, they’re a little more abstract. I’m the yin to her yang. Being different from my mom was never a problem, really. Of course, we did butt heads from time to time, but we mostly understood one another and accepted each other for who we are. What I didn’t expect, however, was that time would reveal that I was much more like her than I had ever expected. I never anticipated that I’d notice myself sounding just like her. I was surprised the very first time I caught a glance in the mirror at my adult face, thinking I had spotted my mother for just a second.
Like my mom and me, mothers and children share a lot, no matter how different they may seem. It’s inevitable. Whether learned from watching them or passed down through genetics, children are destined to inherit certain traits from their parents. Unfortunately, there are also certain health risks that are more likely to be passed from mothers on to their sons and daughters.
The Science of Inherited Traits
In the nucleus of each cell in the human body, you can find the chromosomes you inherit from your parents. You have 23 pairs of chromosomes, with one half of each pair from one parent and the other half from the other. These chromosomes determine what traits you inherit, like the color of your eyes. What traits you inherit from which parent really depends on a lot of things. Some genes are dominant, which means they get priority over other genes no matter which parent they come from. It isn’t just physical traits that get passed from parent to child, according to the United Kingdom’s National Health Service. If there are mutations on a gene, those mutations may be inherited by the child. Of course, genetics are not completely to blame: Many conditions are random or caused by environmental factors, according to Erin O’Toole, MS, a certified genetic counselor and the owner of Family Forecast. “Down syndrome, for example, is a typically random event but does tend to happen more frequently as mothers get older,” she explains. “If a mother or father is personally affected by a genetic condition, a child is typically at increased risk, but this risk would change depending on the condition.” Additionally, sometimes genetic conditions are simply carried by a parent, who remains unaffected, but they can pass on the condition to their child. And there are some conditions that require both parents to be carriers for the child to be at risk, while others require only the mom or only the dad. When it comes to physical traits, it’s kind of a toss up whether mom or dad passes on a certain trait. What we do know, however, is that there are a few traits and conditions that are more likely to be passed from mom to child. In some cases, it’s all genetic. In others, it’s about the environment the mom provides during pregnancy and early childhood.
Apple or pear?
One’s body type can be inherited from their mother, according to a study published in the journal BMC Biology in 2014. In this study, they discovered that two specific imprinted genes influence the composition of muscle and fat in the body of mice. And one of those imprinted genes, known as Grb10, was linked to an increased risk of obesity and a glucose intolerance in those mice. So what does this mean for humans? Scientists believe further research should take place to examine the possibility that maternal genes and paternal genes are working against each other to determine body composition with maternal genes linked to higher body fat.
Just Like Mom
When it comes to fertility in women, a genetic link may exist between mom and daughter. Specifically, the age of mom as she begins menopause might have a correlation with infertility in her daughter. According to a study published in the journal Human Reproduction, the number of eggs left in a woman’s ovaries decreases more quickly in the daughters of women who enter menopause earlier in life. This is an important aspect of fertility, since we know that egg count and quality decreases as women grow older.
It’s in Our Blood
Women who carry a specific blood disorder might pass that disorder onto their sons. Hemophilia is a clotting disorder that causes abnormal bleeding, most frequently experienced by men. This is a genetic disorder that is carried on the X chromosome. When a mother only has one hemophilia gene, she carries the disorder but doesn’t exhibit symptoms. If she has a son, he will inherit hemophilia from her and, since he only has one X Chromosome, he will experience the symptoms of this clotting disorder, according to the National Heart, Blood, and Lung Institute.
Mental Health Issues
Prenatal depression is believed to be experienced by as many as 23 percent of expecting moms, according to research published by the American Pregnancy Association. Many mothers experience symptoms that go well beyond nervousness about the new baby, experiencing hopelessness, mood swings, and even anger. [pullquote align=”center”]“Having a parent with a mental health condition does increase the risk for a child, but we are still often unable to determine the extent of the increase.”[/pullquote] Unfortunately, it is believed that many moms go undiagnosed or untreated. We know that prenatal depression does influence the health of a baby. It is linked to negative birth outcomes like problems with development and lower birth weights. There is also an increased risk for the child developing mental health problems later in life, although research is still inconclusive on how much this risk is increased, according to O’Toole. “Mental health conditions, including depression, are categorized as ‘multifactorial’ conditions, meaning they are the result of multiple genetic and non-genetic factors,” she explains. “Having a parent with a mental health condition does increase the risk for a child, but we are still often unable to determine the extent of the increase.” For parents who are concerned because of their own mental health background, she suggests a discussion with child’s pediatrician so both parents and doctor can be on the lookout for symptoms and discuss early intervention if needed.
A Scary Cancer Gene
Certain mothers pass a high risk of breast cancer on to their daughters. Specifically, there are two gene mutations that are increased with a higher likelihood of developing breast cancer and ovarian cancers Certain mutations of the genes BRCA1 and BRCA2 are passed from mother to daughter and are responsible for an estimated 20 percent of hereditary breast cancers and 15 percent of ovarian cancers, according to the National Cancer Institute. Of all the women who inherited the BRCA1, between 55 and 65 percent will end up with breast cancer. This is a staggering number when you consider that 12 percent of the general population of women are diagnosed with breast cancer. When it comes to the BRCA2 mutation, around 40 percent of women who inherit this mutation go on to develop ovarian cancer. The good news is that the mutations are not common, so only those with a family history of women being diagnosed with breast cancer or having already tested positive for a specific mutation need to receive testing genetic testing.
When should I have genetic testing?
For expecting mothers, it is important to understand that passing on genetic conditions is not a common experience. Most mothers experience healthy pregnancies and give birth to healthy children. [pullquote align=”center”]Would I want to know in advance if I were going to have a baby with a genetic condition?[/pullquote] However, it is always it a good idea to understand if you have risk factors for passing on a genetic condition to a child. Although O’Toole suggests genetic counseling to all mothers, she says there are specific clues that a mom should definitely have genetic screening. “Being over 35, having a family member with a genetic condition, or having a history of a poor pregnancy outcomes are all reasons to consider genetic screening,” she explains. Additionally, she believes all moms who may conceive or are currently pregnant should spend time asking themselves hard questions about what they want to know about their unborn child and how those answers will influence her choice to have genetic screening. “Asking questions like, ‘Would I want to know in advance if I were going to have a baby with a genetic condition? Would this information change how my family and doctors prepare for the birth and newborn period? Would I consider ending the pregnancy or creating an adoption plan?’ can help you decide if you want to explore your testing options more with your doctor or genetic counselor.” And, for women who are dealing with anxiety about their pregnancy, a genetic screening that reveals that mother is low-risk can be the reassurance she needs to enjoy her pregnancy without the overwhelming fear of the future of her baby’s health. Knowing her baby has a low-risk of inheriting a life-changing condition just might mean less time worrying and more time daydreaming about whether they’ll get mom or dad’s eyes.