A Genetic Diagnosis Illuminates a Troublesome Symptom
When Carson Meile was in kindergarten, in South Dakota, he developed a frightening condition. He experienced severe cycles of vomiting that lasted several days, putting him in the hospital several times over the course of a year.
Doctors struggled to figure out was wrong. They speculated that it was an unusual presentation of strep throat or perhaps a psychological issue. (Carson would not swallow his saliva when he was having an episode.) A specialist eventually diagnosed Carson with cyclic vomiting syndrome. But no one knew what caused it.
Carson, now 12, also has developmental delay and autism. His parents wondered if those conditions were linked to the vomiting. Doctors dismissed the idea. The Meile family had discussed genetic testing with Carson’s doctor. But their insurance didn’t cover it, and their doctor was doubtful they would get a result.
Then the family learned about SPARK through a support program in their state that helps families with children with disabilities. “I thought, this is our chance,” says Sharon Miele, Carson’s mother. “I felt this was something that God placed in our laps.”
Last year, Carson got a genetic diagnosis through SPARK. He has a change in the POGZ gene, which has been linked to both autism and vomiting. The
The POGZ gene is active in the brain and helps to regulate the activity of other genes. In addition to autism, changes in POGZ are linked to speech and language delay, vision problems and low muscle tone, among other issues.
Carson’s genetic change is extremely rare. Doctors first described the condition, also known as White-Sutton syndrome, in 2015. Only about 50 people have been diagnosed to date. As is the case for most POGZ changes, Carson’s genetic change was de novo. That means he didn’t inherit it from his mother or father — it occurred spontaneously during development.
Sharon Meile says that getting the genetic diagnosis has helped make sense of her son’s medical history. The list of symptoms typically found in people with POGZ changes was particularly enlightening. “It was amazing how many of those symptoms that Carson had,” Sharon says. Indeed, Carson wasn’t alone in having vomiting issues. A small study of people with POGZ changes, led by SPARK’s principal investigator, Wendy Chung, found that nearly half had cyclic vomiting.
Soon after getting the genetic result, the
Parents can find out if other families are having similar problems and get advice on what has helped other children. “Every child is different, and some things that worked for their child didn’t necessarily work for ours,” Sharon says. “Passing some of the information to doctors has been helpful.”
Earlier this year, two families whose sons had been diagnosed with the condition launched a family advocacy group called the White Sutton Syndrome Foundation. They were inspired in part by Vernon Sutton, a pediatrician
Sutton says that family groups can be instrumental in gathering information about rare conditions. Their input can also highlight what symptoms are most challenging for families. For POGZ, families report that sleep and gastrointestinal issues can be particularly difficult. Sutton’s team is currently surveying families on these issues.
A SENSE OF RELIEF
Sharon says the genetic diagnosis hasn’t had a direct impact on Carson’s medical care. He was already getting various types of therapy, including speech, physical and sensory therapy. But the diagnosis was a relief for the family. “My husband and I always blamed ourselves and wondered if it was something we had done,” she says. “That’s been really reassuring for both of us.”
The genetic diagnosis has also eased some of the
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Spectrum provides comprehensive news and analysis of advances in autism research. Funding for Spectrum comes from the Simons Foundation Autism Research Initiative (SFARI), but the team is editorially independent.