Wisconsin Is In The Forefront Of Genetic Screening, So Infant’s Disorder Was Spotted And Treated.
Patricia Simms, Wisconsin State Journal
Reprinted by Permission
Myles Tesky is an unlikely traveler on the frontier of genetic screening.
Myles, son of Joel and Amanda Tesky of Deerfield, will celebrate his first birthday on April 11. At 11 months, he stands alone, waves bye-bye, plays patty-cake.
“He’s growing just dandy,” said Dr. Jon Wolff, director of the Biochemical Genetics Program at the Waisman Center.
But Myles’ progress is a gift of place and time. Diagnosed by a blood test at birth, he is one of six or seven infants born in Wisconsin every year with a genetic enzyme disorder called medium-chain acyl CoA dehydrogenase deficiency or MCADD.
All states do newborn genetic screening — some test for as few as four disorders, others for 20 or 30. Wisconsin was among the first to start testing for MCADD in 2000, but about half the states do not.
Wolff, an expert in treating metabolic disorders in children, said what’s being done with Myles is the vanguard of genetic screening. “Prognosis is excellent,” he said, “and we should be able to prevent him from have any serious consequences from episodes. He will grow up to be perfectly normal.
“Without knowing that he has MCADD, he would have had about a 30 to 40 percent chance of ending up dead or mentally retarded.”
Chalk up what looks like a success story for Wisconsin’s newborn screening program, for an innovative treatment team at the Waisman Center and for improving blood analysis technology.
“It’s a real sweet spot in terms of everything coming together,” Wolff said.
Newborn genetic screening started in 1961 when Dr. Robert Guthrie of the State University of New York at Buffalo developed a laboratory test to detect phenylketonuria (PKU) in newborns.
An inherited metabolic disorder, PKU results in profound mental retardation if left untreated. In 1963 Massachusetts became the first state to mandate screening for PKU. All states now test for PKU and congenital hypothyroidism.
In the 1990s, tandem mass spectrometry arrived, a technology that allowed screening for about 30 disorders from one tiny blood sample. Wisconsin acquired the technology — in April 2000, Wisconsin added screening for MCADD to its menu, increasing the total of newborn tests from seven to 21. Last year, Wisconsin added five more, bringing the total to 26, said Ron Laessig, director of the Wisconsin State Hygiene Laboratory.
The charge: $65, usually covered by insurance, Laessig said.
Laessig’s voice turns possessive when he talks about Myles and babies like him. “We take ownership when we find one of these babies,” he said. “It’s really critical when you find one of these children with a potential disorder that they have a very clear way of getting into the system.”
Clear-eyed and mellow, Myles attends day care while his parents work. His dad is training to be a paramedic, his mom is the assistant manager at Williams-Sonoma.
About 3 a.m., his parents give him a bottle, then put him back to bed. Going without food for too long could send this baby into a coma.
Children with a fatty acid oxidation disorder have trouble burning fat for energy. This can lead to vomiting, low blood sugar or more serious problems — some babies thought to have died from Sudden Infant Death Syndrome (SIDS) have been found to be victims of MCADD, Laessig said.
MCADD is insidious, he said. “It’s not obvious when you look at these babies, but when one of these children gets sick and stops eating . . . an MCADD child will die because they cannot mobilize their stored fat, their energy resource.”
Myles has a letter from Wolff in his diaper bag — if he has to go to the hospital for intravenous fluids, the letter explains his condition and the appropriate treatment, Amanda said.
The Teskys have taken Myles to the hospital twice in the last 11 months — once when he had a hard time transitioning from breast milk to formula, another time when he had a flu. Both times, the signal was vomiting.
“The main thing is that if the patient starts to have an episode’ which involves vomiting and lethargy that they receive IV fluids with glucose to prevent the hypoglycemia that can occur,” Wolff said.
“Diabetics have a warning when their blood sugar drops,” he said. “But with Myles, he’ll just hit the wall. We don’t have much warning. It will just drop.”
Eventually, Wolff said, the child’s metabolism matures, and the danger evaporates when the child is 2 or 3.
MCADD, which occurs in about one for every 17,000 births in Wisconsin, is autosomal recessive, Wolff said. Both parents must carry the gene for a baby to inherit it.
“It is just a matter of luck or bad luck,” Wolff said. “Both parents are carriers of the defective gene, and when they make an egg or sperm, the sperm or egg has only one of the parents’ two copies of the gene so that is a 50 percent chance.” That translates to a 25 percent chance of each child being affected, he said.
Each of us carries about 10-20 different defective genes, he said. “So, it is just a chance of us marrying someone with the same defective gene.”
The staff at the Waisman Center says the main treatment for MCADD is nutrition.
“Myles, and other MCADD patients, are required to follow a low-fat diet,” said metabolic dietitian Michelle Johnson.
“We generally recommend that 25 percent of their total caloric intake for a day come from fat. This is a diet he will have to follow for life.”
Screening for a wide panel of disorders remains controversial, and states have been slow to adopt the new technology, largely because of cost and the small numbers of babies who benefit.
“A state that is relatively poor and not progressive might decide it costs too much,” Laessig said. “In addition, the technology requires a very expert chemist, and the follow-up requires a medical community that has the expertise to deal with the situation.”
Some states are waiting for evidence that catching the disorders early helps in the long run.
Wolff is doing a five-year study of that. So far, it looks like a success story.
Joel Tesky says he’s happy Myles was born in Wisconsin.
Adds Amanda, “And in this time frame.”
Contact Patricia Simms at firstname.lastname@example.org or 252-6126.