(This story corrects affiliation in paragraph 3 to Children’s Hospital of Philadelphia)

By Carolyn Crist

(Reuters Health) – If a child has developmental disabilities or delays in motor, speech or cognitive function, a pediatrician may recommend a genetic consultation and genetic testing, doctors write in a new patient resource published in JAMA Pediatrics.

These tests may also be useful in caring for children with structural birth defects or chronic functional problems that affect vision, hearing, movement, seizures, mood issues, immune problems, poor growth, digestive issues, hormone problems or heart rhythm irregularities, the authors write.

“We want to empower families to have more information, and so much has changed about what it means to get genetic testing and what it can do,” said Dr. Marni Falk of the Children’s Hospital of Philadelphia in Pennsylvania, who co-wrote the patient resource.

“Sometimes pediatricians aren’t comfortable explaining why testing is needed,” she told Reuters Health in a phone interview. “Genetic testing can be complex but should also be accessible to parents.”

The new patient page (available for free: https://bit.ly/2EUbMrk) offers practical advice about the process, risks and benefits of genetic testing for children.

Falk and her coauthor briefly explain how genetic disorders can be inherited through mutations in parents’ chromosomes, or the mutation can occur spontaneously in the child’s chromosomes.

Today, researchers can identify nearly 7,000 disorders caused by one or more mutations in a single gene. Doctors can test for these mutations to confirm a diagnosis and help parents understand what was inherited, as well as how that may affect future childhood development or healthcare decisions.

Importantly, these tests differ from the popular mail-order tests that identify ancestry and risk factors for disease, Falk said. Instead, tests ordered through a genetics specialist look specifically at the child’s genome to identify mutations in particular genes that are known to cause issues.

“Historically, only the most severe cases that matched textbook definitions were diagnosed, but now we can see that many syndromes have a range of symptoms, and genetic testing can help us identify it,” Falk said.

Once identified, information about an inherited disease may open doors for families to consider gene-targeted therapies or trials for drugs that are in development, the resource points out.

New technologies have also made processing of genetic tests faster, which has reduced the cost. More insurance companies now cover the testing for children.

Understanding the cause of a child’s medical problem can also remove a sense of blame or guilt that children or parents feel when wondering why a disease happened.

“Nobody can control genetics, and nothing you ate or drank while pregnant made these mutations occur,” Falk said. “It can be very therapeutic for parents to realize that.”

Testing can also help parents to assess their risk with regard to future reproductive choices. When families find out that the risk of recurrence in another child is low, for instance, they may consider having another baby.

“Some parents say they can’t possibly have another child with complications and won’t try, even if they want more children, but instead of being scared that it may happen again, they should have accurate information about the risk for another child,” said Dr. Margaret Adam of the University of Washington School of Medicine and Seattle Children’s Hospital.

Adam, who wasn’t involved with the patient resource, is editor-in-chief of GeneReviews, an online collection of reviews explaining diagnosis, management and genetic counseling for inherited conditions. Falk recommends GeneReviews as a source of information about genetic testing.

“There certainly has been a shift in the acceptance of genetic testing, likely because it wasn’t as advanced as it is now,” Adam told Reuters Health by phone. “People who escaped diagnosis before now fit on a spectrum, and we have drugs that can work for different pathways that we didn’t imagine even 20 years ago.”

SOURCE: https://bit.ly/2EUbMrk JAMA Pediatrics, online February 25, 2019.