Children today live in a world where it is becoming easier and cheaper to sequence their genome — the full set of biological material inherited from our ancestors that plays a major role in our development, functioning and behavior. A few businesses have made whole-genome sequencing available to the general public. Curiosity, or a family history of illness, may motivate parents to purchase these tests for themselves or their children.
But what about the risks?
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 and limitations of the testing, and the possible unrelated findings that may arise, says Louanne Hudgins, MD, chief of medical genetics and director of perinatal genetics at Lucile Packard Childrens Hospital Stanford.
For parents who may want to purchase direct-to-consumer, whole-genome testing, Dr. Hudgins encourages careful consideration before making the buy — and offers these important tips:
1. Genome tests often identify sequence variants for 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 childs autonomy — their independent right to decide for themselves whether they want to have information about their future health revealed.
2. If your child is healthy, its worth questioning your motivations to test. Consider what are you looking for, and why. In a healthy child, says Hudgins, who is also a professor of pediatrics and medical genetics at the Stanford University School of Medicine, youre 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 genetic testing and who can interpret the results.
3. Consider the long-term privacy of your childs (and your own) health information. Who will have access to the results of your childs test, and how will those results be used? The privacy policies of the testing companies vary widely and can change over time, potentially leading to exposure of your childs 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 genetic testing.
4. 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 prove conclusive. Most doctors prefer to do specific genetic testing for patients based on known risk factors.
5. 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.
6. 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, Hudgins says. 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.
7. Most direct-to-consumer genome testing companies 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.
Click to read a statement co-authored by Dr. Hudgins on direct-to-consumer whole-genome sequencing, courtesy of the American College of Medical Genetics.
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