Children today are born into a future their grandparents could have only imagined: scientists have sequenced the entire human genome — the full set of biological material inherited from our ancestors that plays a major role in our development, functioning and behavior — and a few businesses have made whole-genome sequencing available to the general public at affordable prices. Curiosity, a family history of illness or the simple notion that knowledge is power may motivate parents to purchase these tests for themselves or their children. But, as Louanne Hudgins, MD, chief of medical genetics and director of perinatal genetics at Lucile Packard Children’s Hospital Stanford explains, there are unique risks to direct-to-consumer, whole-genome sequencing for children.
“I strongly advise parents against whole-genome testing for their children unless performed in the context of a medical evaluation following formal counseling regarding the utility, limitations and possible unrelated findings,” says Dr. Hudgins.
While whole-genome testing has the potential to pin down countless details of who we are — everything from our hair and eye color to our risk for certain diseases — it may also unlock mysteries we cannot solve, surprise us with information we don’t want, create undue anxiety and even hand over our private health information wholesale to the company doing the testing. Screening for specific disorders has become routine in pregnancy, and many babies undergo newborn genetic screening to identify certain conditions that are difficult or impossible to detect any other way. But personal genome sequencing is not specific — it gathers all genetic data into one enormous report, with little or no context. Buyers are presented with a trove of genetic information that may be difficult or even impossible to understand — and possibly difficult to cope with.
For parents who may want to purchase direct-to-consumer, whole-genome testing, Dr. Hudgins encourages careful consideration of the following issues for their children, as well as those outlined in the American College of Medical Genetics Statement on Direct-to-Consumer Genetic Testing:
- Genome tests often identify sequence variants associated with adult-onset disorders. While this knowledge may, in adulthood, assist with medical care, it could be a profound and premature psychological burden to parents and children. It also fails to honor the child’s autonomy—their independent right to decide for themselves whether they want to have information about their future health revealed.
- If your child is healthy, it’s worth questioning your motivations to test. Consider what are you looking for, and why. “In a healthy child,” says Hudgins, “you’re more likely to find inconclusive results that will cause you unnecessary anxiety.” For children with concerning symptoms or undiagnosed diseases, Hudgins suggests working directly with a medical care provider who understands the utility and limitations of the testing and who can interpret the results.
- Consider the long-term privacy of your child’s (and your own) health information. Who will have access to the results of your child’s test, and how will those results be used? Companies’ privacy policies vary widely and can change over time, potentially leading to exposure of your child’s private health information. Parents should have concerns about the commercializing of personal genetic information similar to the way social media sites and search engines collect, store and share information about their users. Some direct-to-consumer genome testing companies reserve the right to use the personal health information that they gather during testing.
- Genome tests are likely to identify “sequence variants of unknown significance”—results that may depend on the medical history of the family or other factors to be conclusive, which may depend on decades of future research that produces unexpected or unwanted results, or which may never be conclusive at all. Most doctors prefer to do specific genetic testing for patients based on known risk factors.
- Finding a sequence variant of unknown significance in a child may be a signal to look at the genetic sequence of the parents, which can sometimes lead to surprises for the family. Hudgins explains that is not uncommon to discover situations of non-paternity (mistaken fatherhood) or even to identify instances of “homozygosity”—when parents turn out to be related by blood.
- Whole-genome tests may reveal that your child has a change in a gene predisposing him or her to a disease, such as autism. “This does not mean that your child will become autistic,” says Hudgins. “It means that, in large population studies, specific changes in that gene were associated with an increased risk of autism. But it is not a guarantee, as expression of each gene is influenced by a variety of individual factors.” While some results may provoke unfounded worry, others may provide false reassurance.
- Most direct-to-consumer genome tests do not have genetic counselors available to interpret results, leaving parents with an enormous amount of information about their child that they cannot interpret on their own. Research-quality testing, interpretation and analysis can take up to 100 hours and cost around $17,000 per person, according to a recent study by Stanford scientists published in the Journal of the American Medical Association. The study also showed that the current technology used for whole-genome sequencing is not yet as accurate as it needs to be.
In a research setting, whole-genome sequencing has the potential to decode our personal mysteries through millions of genetic clues. But, with knowledge as powerful as this, scientists and parents alike must carefully weigh the right timing, privacy concerns, unpredictable outcomes and potential benefits when it comes to children.
Reprinted with permission from Stanford Children’s Health.
Julie Greicius, MFA is editorial director at Stanford Children’s Health and Lucile Packard Children’s Hospital Stanford.