MU rapid-response team saves newborns in Mennonite communities
MU volunteers help babies born with a genetic condition known as maple syrup urine disease. The metabolic disorder disproportionately afflicts members of Old Order Mennonite communities, including those in rural Missouri. Photo from Clipart.com.
Emergency phone calls are rare for most molecular-biology and biochemistry researchers. But when the phone rings at 3 a.m. for Charlotte Phillips, she answers it immediately. A child’s life might be at stake.
Phillips is part of a team of University of Missouri volunteers who, for more than a decade, have worked to save babies born with a devastating genetic disease known as maple syrup urine disease (MSUD). The rare condition affects an estimated one in 225,000 infants nationwide. But in Old Order Mennonite populations, such as those in rural Missouri, the incidence is about one in 150 newborns. If these infants don’t receive a special prescription infant formula within three days of birth, they suffer brain damage. Untreated, most die within two weeks.
Complicating the situation is the isolated, simple farm lifestyle the Mennonites live. Most Mennonites don’t drive, and some don’t own telephones. Babies generally are born at home or in rural clinics, and several hours, if not days, might pass before a newborn is tested for MSUD.
This is where the informal team of MU physicians, dieticians, sociologists and geneticists comes in. The experts identify families at risk, provide counseling, set up elaborate relay teams to get blood samples from newborns to specialized testing facilities in Columbia, and then rush news back to the family if the baby needs treatment.
A four-gene problem
MSUD is an inherited disorder that renders the body unable to process certain amino acids from protein. The urine of affected infants has a distinctive, sweet odor, like burned caramel, which gives the condition its name.
MSUD develops when mutations occur in one of the four genes that direct certain proteins to break down amino acids in foods such as milk, meat and eggs. As a result, excesses of certain amino acids and byproducts build up in the body. High levels of these substances are toxic to the brain. Damage begins within 72 hours after birth, when the brains of affected babies begin to swell. A baby with the condition can lapse into a coma and die from neurological complications.
There is no cure. Treatment must begin soon after birth, with a baby formula that contains necessary nutrients but none of the offending amino acids, allowing babies to develop normally. Adults with MSUD use a similar dietary formula as their primary protein source, too.
MSUD disproportionally affects the Mennonite community because members tend to marry within a relatively small population. The MU team maintains close ties with the Mennonites near Versailles and Memphis, Missouri towns with the largest Mennonite communities.
“We can’t not do the testing; it is too important.”
—Professor Charlotte Phillips
While babies born in hospitals can be tested for MSUD immediately, the Mennonite practice of giving birth at home, often far from major medical centers, slows identification of the disease. The type of test most commonly used to detect MSUD further impedes speed. Blood is sampled 12, 24, 48 and 72 hours after birth to note accumulation of offending amino acids and confirm the diagnosis. Under the best of circumstances, this test takes too long. Additional delays, such as communicating via horse-drawn carriage, exacerbate the problem.
A faster diagnostic test had to be devised.
An ad-hoc MU team formed in 1995 in response to 1993 incidents in which two babies almost died. Richard Hillman, a physician and medical geneticist, sought out Phillips to help develop a DNA-based MSUD test. Phillips, an associate professor and clinical molecular geneticist in MU’s Department of Biochemistry and College of Agriculture, Food and Natural Resources, specializes in researching inherited and acquired diseases of the bone and kidney. Rural sociologist Joel Hartman, dietitians and medical students rounded out the initial group.
Jonathan Dyer — then an MU biochemist, now a School of Medicine graduate — helped develop that initial test. Later, Phillips worked with genetics graduate student Latisha Love-Gregory to better track the MSUD gene in the Versailles Mennonite population. The researchers were able to go back 10 generations and find common ancestors to provide important scientific clues.
The DNA assay the team developed was significantly faster — delivering confirmation in 12 hours. An even faster test more recently developed provides results in as little as five hours.
Unfortunately, the new assay developed by Phillips and her post-doctoral fellow, Stephanie Carleton, requires use of an expensive, hard-to-attain piece of equipment. Elizabeth Bryda, an MU veterinary pathobiologist, uses such a DNA device in researching genetic diseases. She drops everything when an at-risk baby needs testing.
The test, like the program itself, has been “creatively” funded during the last 14 years, Phillips says. A $100,000 grant from the National Institutes of Health helped, as did donations from the Children’s Miracle Network, the Leda J. Sears Trust Foundation, MU Healthcare and, most recently, the Heartland Genetics and Newborn Screening Collaborative.
“We operate on a shoestring,” Phillips says. Despite financial obstacles, the team persists. “We can’t not do the testing; it is too important.”
While the assay was a major step forward, a problem remained. Because MSUD is rare, most regional hospitals don’t maintain DNA assay equipment. Here is where the ad-hoc group of MU volunteers came together to form a rapid-response team.
A DNA ‘bucket brigade’
Helping the scientists and healthcare personnel are other volunteers who work with the Mennonite community and watch over at-risk pregnant women. When a baby is delivered, these volunteers rush the newborn’s DNA sample to Columbia. After the sample has been assayed, the news to either give or not give the special formula goes back to the parent via the volunteers.
“One of the first families that we worked with lived in northwest Missouri, five hours from the nearest major medical center,” Phillips says. “We knew both parents were carriers, which meant their offspring had a 25 percent chance of developing the disease. As the family did not have a telephone or car, we had to pre-arrange, like a kind of water-bucket brigade, a series of team couriers to bring the baby’s DNA sample to Columbia, where we could conduct the test.”
Twenty-four hours after the baby was born, the team had the DNA sample. The baby had MSUD. “We telephoned the results to a pre-positioned volunteer near the Mennonite community who delivered the news to put the baby on sugar water and bring him to University Hospital,” Phillips says. “At 41 hours old, the baby was placed on diet, and he did beautifully and had no neurological impact. But this baby was the driving force for us to develop the even-faster five-hour assay that we are currently testing.”
Though operating on a patched-together budget, the team is looking to expand its services to other Mennonite communities. Phillips and Dawn Peck, an MU genetics counselor, are co-principal investigators in a community-outreach project targeting eight states with Mennonite communities. Working with them is Julie Grasela, a clinical nutritionist.
Though funded on a shoestring, using borrowed scientific equipment and maintaining an informal network of volunteers, the program has been successful. Since its start, the team has not lost a baby to MSUD — even when the calls for help come in at odd hours.