(photo credit: Tarah Tamayo, Flickr, Creative Commons)
A WSU researcher will study whether children with a specific enzyme deficiency can safely drink milk.
Speech and Hearing Sciences Associate Professor Nancy Potter (pictured, left) is embarking on a new quest designed to help children with a genetic disorder known as Duarte galactosemia (doo-AR-tay guh-LACK-tuh-SEE-me-uh). It’s a genetic variant of a potentially fatal disease known as classic galactosemia.
Potter’s co-investigator, genetics researcher Judith Fridovich-Keil at Emory University in Atlanta, was recently awarded a grant from the Patient-Centered Outcomes Research Institute to study Duarte galactosemia. Their project will build on a small pilot study they conducted in 2014.
During the next two years, Potter, a fellow speech-language pathologist from Coeur d’Alene, Idaho, a project manager and two post-doctoral researchers in psychology will take to the road, often. They will travel for one week each month to at least 16 states to test children, ages 6-12, half with Duarte galactosemia, half siblings who don’t have it, to serve as a control group.
“It’s the third project in my career where I’m doing research out of a suitcase,” Potter said.
Potter’s team will test children’s speech, motor, cognitive and behavioral outcomes. They will also interview parents of children with Duarte galactosemia to find out what they fed their children as infants and how the children have developed.
Timing is crucial
Within 48 hours after birth, all babies in the U.S. have a few drops of blood drawn from their heel. These samples are collected on filter paper and sent to the lab, where technicians test the blood for about 30 – and sometimes more – genetic disorders, including galactosemia.
People with the classical form of galactosemia produce 1% or less of the enzyme they need to break down galactose, one of the sugars that make up lactose, the sugar in milk. Newborns are tested, but if not diagnosed in time, and still fed breast milk or formula, the galactose byproducts build up in their blood. That can lead to organ failure and death within days or weeks. Even when detected early, more than half of the children with classic galactosemia have neurological disorders.
Duarte galactosemia isn’t considered to be as serious, although it is far more common (one-in-5,000 children have it, compared to one-in-50,000 for classic galactosemia). Children with Duarte galactosemia have up to 25% of the enzyme for breaking down galactose. Some children with it experience no adverse health issues, others probably do. But Potter says little is known about how Duarte galactosemia affects children and few scientists have done any research on it.
So, when a child is diagnosed with Duarte galactosemia, how does a doctor counsel its parents? Depends on the state, Potter says.
“If there’s no research and you don’t know if milk is poison to your baby or not, you’re going to have tremendous anxiety about whether or not your child should be breastfed or be given a milk-based formula,” she said.
“In Georgia, you will be informed that your child has Duarte, told to keep your child off milk for the first year of life, and then before age 2, have your child tested to see if milk can be tolerated,” she said. “In Washington you will be told your child has Duarte galactosemia, but you can breastfeed or use a milk-based formula. In several states, you are not informed that your child has Duarte galactosemia.”
Potter hopes the study will provide physicians and scientists with enough information to allow them to create evidence-based recommendations for parents of children with Duarte galactosemia.
“With social media, parents of children who have Duarte galactosemia are connecting and reporting some of same disorders as classic,” Potter said. “But we don’t know if Duarte increases the risk for developmental disorders and if so, which disorders, speech, motor, cognition or tremors?
“We hope to learn if there’s a higher prevalence of problems in Duarte galactosemia? And if so, are they related to diet in the first year of life?” she said.