Pregnancy is exciting and terrifying. Expectant mothers picture their lives when they are finally able to hold the baby growing inside of them in their own arms. But many also worry about making sure their babies are happy and healthy. Some moms-to-be may choose to have genetic testing done during pregnancy to identify potential genetic disorders or chromosomal abnormalities.
As more families choose this option during pregnancy, Duke University School of Medicine researcher Jennifer Cohen, MD, assistant professor of pediatrics, collaborated with Nina Gold, MD, at Massachusetts General Hospital to propose a list of genetic conditions that would be useful to know about in the prenatal timeframe to improve medical outcomes prenatally and postnatally. Their report was published in the American Journal of Human Genetics on April 9.
Cohen’s expertise is in the prenatal timeframe, while Gold’s is in early postnatal. Together, with a team of subspecialty experts, they created a treatable fetal findings list that encompasses genetic conditions in which there is a good chance of intervening early. These include conditions that have interventions being tested in a clinical trial, have been reported in case reports with some success, or affects labor and delivery management. This list only focuses on single gene diseases and disorders that are considered to have treatments with proven or plausible efficacy and safety.
“The whole purpose of creating this list,” Cohen said, “is seeing what genes would be useful to know about prenatally because treatment in utero or in the first week of life can have the biggest positive impact on the patient.”
Traditional newborn screening can catch some of these conditions, but it can take weeks to get results back. Having that information prenatally may not mean it can be treated before birth, but it does mean that doctors could begin treating it immediately following the birth.
“If a patient is already getting exome or genome sequencing during pregnancy,” Cohen said, “this list could be considered for secondary or incidental findings.” Some of these findings may not be present on an ultrasound, but, Cohen said, “they have such a simple medication, such as giving the mother vitamins or a supplement that will help long-term.”
Early onset lysosomal storage diseases, for example, cause a buildup of toxic materials in cells due to a specific enzyme deficiency and can lead to developmental delays, physical deformities, breathing difficulties, seizures, and death Early detection and treatment are paramount, and if doctors can begin an in utero enzyme replacement therapy, currently in clinical trials, for these diseases, they can provide the child a much more normal life.
This list can also expose genes that can cause complications in labor and delivery. Armed with this information, expectant mothers can plan for a C-section or avoid vacuum assistances or forceps delivery to avoid brain bleeds.
It can also help with finding hypoglycemia in newborns, which, if not found quickly enough, can lead to a potentially fatal series of events like liver and heart failure. While this can’t be fixed in utero, the treatment is simple: feed the baby formula until the mother’s milk comes in.
The overall goal of the fetal treatable findings list is to help deliver more healthy babies. “This list will change over time,” Cohen said, “and hopefully, the outcome will be a living document that will change with time as more treatments are approved and discovered.”