Two rare but ‘devastating’ conditions added to newborn screening list

The Washington Department of Health announced two additional newborn screening rules on Friday, adding Pompe disease and Mucopolysaccharidosis type I (MPS I) to the list of mandatory conditions.

Spokane County Health Officer Bob Lutz said both enzyme deficiency-related conditions are rare, but an early diagnosis can greatly affect a patient’s trajectory.

“They’re really rare, but they’re devastating if you don’t pick them up,” Lutz said. “Very uncommon, but if you can screen for a child and save a child, then it’s worth the effort.”

Of approximately 85,000 to 88,000 births in Washington a year, around 200 are diagnosed with the 29 different newborn screening conditions. Pompe disease is estimated to occur in 1 of every 40,000 births. The incidence of MPS Iis 1 in 100,000. There is no cure for either, but early diagnosis greatly improves the effectiveness of treatment.

Dr. Katheryn Hudon, a pediatrician with Providence Grand Pediatrics, said patients with Pompe disease experiencean issue with the enzyme responsible for breaking down glycogen. Normally, the body converts glycogen to glucose, which is used for energy. For those with Pompe, the glycogen builds up in toxic amounts in the areas it’s normally stored: the liver and muscles.

“If we have no idea that this is happening – the infant with a very early onset problem – that is very hard to recognize,” Hudon said. “By the time we see that they have fairly poor muscle tone, it’s pretty far down the line. How do you tell that an infant has really bad muscle tone? They just lay there all day long.”

Hudon said in the early onset cases, since the heart is in fact a muscle, infants normally die from heart failure before turning one. There are also less severe, later onset versions. In those cases, the child has a small amount of the enzyme needed to break down the glycogen.

The most common – and most severe – disease caused by MPS I was until recently referred to as Hurler syndrome. The symptoms are caused by a lack of an enzyme that creates a buildup of glycosaminoglycans, or GAGs, which are long chains of sugars that are stored all over the body. The buildup causes damage to nearly all organs, but especially the nervous system, skeleton, muscles, eyes and heart.

“These kids have a very distinctive appearance. Wecall them coarse facial features,” Hudon said. “ With these kids, we can treat them with enzyme replacement, but before the newborn screening, most of them didn’t get diagnosed until around the age of five.”

Hudon said that if an infant is diagnosed with one of the 29 conditions on the screening, the parents will be informed right away.

“If you get an abnormal result, they will hunt anybody down within a day and they will get treatment started,” Hudon said. “They’re extremely hyperefficient with these positive results.”

Even though the conditions are rare, Hudon said the test is crucial.

“The reason that we screen for these diseases is because we have a chance to alter the course of the disease process if we start treatment early enough,” Hudon said. “That’s the reason why we’re doing this.”