Severe protein restrictions normally the only way to avoid brain damage and retardation
Imagine being forced to say no to a child crying for more food at supper. Sadly, Margie Fischer doesn’t have to imagine it; that was normal life at her family’s dinner table for years. Her daughter Maggie, now 20, suffers from phenylketonuria (PKU), a genetic disease that means her body can’t tolerate anything more than a low-protein diet.
PKU is described by scientists as an autosomal recessive genetic disease that is characterized by a deficiency in an enzyme called phenylalanine hydroxylase (PAH).
Without PAH, the body cannot metabolize the amino acid phenylalanine. It then builds up in the blood, crosses the blood–brain barrier and causes severe brain damage. Fortunately, PKU can be detected at birth in blood tests, and was one of the first treatable genetic diseases. From infancy, PKU sufferers are restricted to a low-protein diet to avoid the worst complications of the condition. This diet is essential during childhood to prevent damage to the brain while it is still growing; however, it is now also recommended for life to optimize school performance, concentration and the ability to think clearly.