No one ever said Thanksgiving was a healthy day. While we celebrate our gratitude in countless ways, most of us are guilty of overconsumption and sedentariness while we gather with loved ones. But between the helpings of mashed potatoes, third-down conversions and tryptophan-induced comas awaits a powerful, golden health opportunity: a conversation about family history.
Since 2004, the U.S. Surgeon General has advised Americans to take family conversations a step beyond football on Thanksgiving by naming it National Family Health History Day. As a genetic counselor, I am thrilled that the Centers for Disease Control formally recognized the need for us to collect more information about our family member's medical histories, and has even told us when and how to do it. Last month the National Society of Genetic Counselors released a Family Health History position statement also urging physicians and patients to collect this information.
There are a myriad of reasons that we don't know our medical family history. I'm healthy, I never thought to ask. Or, my family has the usual ailments. It's awkward. It's boring. It's scary. It generates a garbled litany of diagnoses, medications, and tests that is barely understandable. And, commonly: it's not polite to pry. But put aside these excuses for a moment, because family history can be an extraordinarily powerful tool for taking charge of your health. These are questions worth asking.
Now more than ever, we understand that nearly every single health condition is either primarily caused by, or its course influenced by, one's DNA. Yet to date, family history is one of very few practical medical tools that can identify disease susceptibilities before symptoms present. It has been termed the "single best genetic test" and is the most cost-effective genetic risk assessment tool. The ability to examine the medical histories of multiple family members at once can assist in predicting patterns of inheritance and diagnosing conditions that present with variable features. Once a family history is presented to a qualified professional, such as a certified genetic counselor, a risk assessment can help determine the magnitude of concern - if any - that exists. Importantly, many people will receive welcome reassurance that there is little to worry about. When appropriate, genetic testing may be offered to refine one's risks. And knowledge is power: options for disease surveillance and medical management can be provided and in many cases can prevent disease or reduce its severity.
But while knowing one's family history is arguably important for people of every age, there is one group who should take the Surgeon General's advice especially seriously: those who are planning to conceive. This is because future parents not only benefit from preparation, but have an extraordinarily unique opportunity to prevent certain genetic diseases from ever occurring in their offspring.
Discussions of genetic screening prior to or during pregnancy tend to be focused on DNA testing and less on family history. Understandably, medical providers may be more comfortable ordering a standard DNA test than interpreting three generations of family folklore. Tests such as those used to identify healthy "carrier-carrier" couples, who have a 25% chance to have a child with a recessive condition, or those used to screen for sporadic chromosomal conditions in a baby, are valuable screening tools. However, they cover a limited number of disorders and in many cases will not address significant concerns posed by family history. Notably, such screening does not test for dominantly inherited conditions (those passed from grandparent to parent, parent to child), so family history is the sole tool for identifying these risks. What's more, in one's 20s-40s - the peak years for reproduction - some individuals who are themselves at risk to develop a familial condition may not yet have symptoms, but could still harbor a mutation that could be passed on to their children. Finally, an accurate history can aid in interpreting findings from genetic testing, since in many cases testing identifies DNA variations that may or may not be truly related to disease risk, but might be better understood in the context of the family's past medical experiences.
Once a pregnancy is conceived, one of the first conversations between physician and patient is about options for genetic screening, and hopefully does include a discussion of family history. But this is late - much too late - for this conversation. While most prospective parents receive reassurance from prenatal screening, those who don't face few choices; namely, preparation for the birth of a child with physical and/or mental challenges, or, if the condition is sufficiently concerning, pregnancy termination.
The preconception period is arguably a far more ideal time to explore genetic risk factors including family history, as the information may impact reproductive planning and choices. Information may be more easily absorbed and decision-making may be less stressful than in the prenatal period, when many women experience significant anxiety around prenatal testing. Wait times for genetic test results are best experienced without the ticking clock of a growing belly. And once pregnancy does occur, patients can take heart in knowing that they have prepared and addressed, to the best extent possible, any areas of concern.
Importantly, when a significant risk is identified, in some cases patients will have the opportunity to prevent the transmission of genetic disease to their future child through a process known as preimplantation genetic diagnosis (PGD). In PGD, patients undergo in vitro fertilization to create embryos in the laboratory; cells can safely be removed from the embryos for genetic testing. This can be done for a recessive condition, such as cystic fibrosis or spinal muscular atrophy, in which parents are healthy carriers, or for a dominant condition such as certain inherited cancers, cardiac disorders, or neurologic diseases. Embryos that test negative for the familial condition can be transferred back into the uterus, thereby significantly decreasing the chance for an affected child. When informed, patients have indicated that PGD is preferred as a viable alternative to prenatal testing and possible termination of an affected pregnancy, and is often associated with less stress.
As well, identification of genetic concerns prior to pregnancy allows for exploration of other options for mitigating risks, including use of an egg or sperm donor, traditional adoption, embryo adoption, or choosing to live childfree. And those who choose to proceed with natural conception will be well-educated about their options for testing - or not testing - the pregnancy prior to birth, and planning ahead for any anticipated medical needs of the baby.
The opportunity to seek the medical histories of our relatives is a time-limited one. While it feels as though there will always be another opportunity to ask, at some point there won't be. In some cases, DNA from relatives can be crucial for interpretation of one's own genetic results. Older or affected family members may even be asked to consider banking their DNA for the later benefit of their family members as they await more advanced testing opportunities. With the current breakneck pace of genomic medicine and discovery, the genetic causes of disease will be increasingly revealed. However, without family members' "genotype-phenotype" correlations - demonstrating whether those with a certain genetic change actually exhibit features of a disease and to what degree - our understanding of genetic findings could still be limited for some time.
So, what to ask your family, and how? Ask several generations about their health; it's more concerning when a disease is seen in multiple generations. Inquire about the ages at which serious illnesses started. Find out the causes of death in your relatives, including - and especially - those who died young, about whom families sometimes talk the least. Medical records or death certificates may be requested to clarify diagnoses. Finally, ask about your family's country of origin, ethnicity, and religious heritage, since some genetic conditions are more common in certain ethnic groups. If you won't be with your family on Thanksgiving - or just to avoid the awkward factor - take advantage of email and social media.
To help you, the U.S. Surgeon General has developed a web-based program for organizing and updating family health history, and the National Society of Genetic Counselors has very helpful tips as well. The health history can be printed and shared with your primary care physician and/or a genetics specialist. Genetics professionals can also help those who have limited or no family history information, such as those who are adopted, those who were donor-conceived, or those not in touch with close relatives, determine what other disease risk factors may be present and whether genetic testing is indicated in the absence of a detailed family history.
Family trees have been used for over 100 years, and it's time to put yours to good use. People are frequently surprised at the receptiveness of their relatives, and you will likely learn much more than you set out to find. Medical experiences rarely occur in a bubble; they have profound effects on people's lives, influencing quality of life, reproductive choices, career paths, personal interests, and values. So your interest in your family's health history is your interest in their lives, and in the lives of your ancestors. Your questions might be met with openness and even gratitude, and, after the pumpkin pie is all gone, just might give you something extra to be thankful for.