Grayson McGill

Toddler Grayson McGill has a rare metabolic disorder where regular food can make him ill.

Chad Farquharson and his husband Wayne McGill must take more care in monitoring their son’s protein consumption for the day than the average parent. The couple must measure the amino acids consumed by Grayson down to the exact milligrams; if they are off, the results could easily be catastrophic.

Grayson has Maple Syrup Urine Disease (MSUD), a rare and potentially deadly metabolic disorder that causes amino acids from proteins to accumulate in the body. Grayson is unable to process three amino acids – leucine, isoleucine and valine. The disease’s saccharine name, which comes from the sweet smell of the patient’s urine, belies the seriousness of the condition. The toxicity it causes can lead to brain swelling, mental retardation, coma and death.

Grayson’s life will hinge forever on his ability to delicately balance the amount of amino acids he consumes each day. He won’t be able to eat cheeseburgers and fries like other kids and his environment can pose a danger. “Playdough has flour in it, and grain has protein,” says Chad. “If he swallows the playdough, it can break down in his stomach and release leucine.” Not knowing what might contain protein is a worry.

Chad and Wayne do not have a medical background, but they have become quick studies in MSUD. Grayson’s diagnosis was made just after he’d undergone open-heart surgery to repair life-threatening defects. The operation was successful, but a few hours later, his new parents were told that he had the disease. A neurologist had noticed subtle swelling in his brain and became concerned about a metabolic condition. Because BC Children’s Hospital began screening for MSUD as part of an extended screening program that now includes 22 conditions, the neurologist’s question was readily answered.

The quick result of the testing meant doctors could instantly respond to Grayson’s dietary needs.

Grayson, with his chubby cheeks and saucer-shaped eyes, looks like a perfectly normal kid. Nobody will believe that he’s forever one chocolate bar away from potential brain damage. “This is what we are concerned about when he goes to school,” says Wayne, sighing. “It’s not like a peanut allergy, so all he has to do is avoid peanuts. I’ll have to be clear: ‘All food can harm him.’”

Thanks to research, though, Grayson has a chance at life that previous generations would never receive. “If we didn’t have screening for MSUD, the diagnosis could have been missed entirely,” says Dr. Vallance, director of the BC Newborn Screening Program. “[Grayson] might have died post surgery and nobody would have known why.”

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