I am writing this commentary as both a parent of two children with phenylketonuria (PKU) and as a professional as the Executive Director of the National PKU Alliance, a nonprofit patient advocacy organization working to improve the lives of people with PKU and pursue a cure.
Most medical professionals know of PKU as a metabolic disorder that is diagnosed through newborn screening. People living with PKU cannot process the amino acid called phenylalanine, found in all natural sources of protein, due to a deficiency in the phenylalanine hydroxylase enzyme. This enzyme converts phenylalanine into tyrosine, another essential amino acid. In turn, tyrosine is important in the production of many neurotransmitters, such as dopamine and serotonin. For decades, professionals and the patient community have discussed PKU as a dietary condition because treatment has centered around medical foods and a restrictive diet very low in protein. However, in essence, PKU is a rare brain threatening disorder as excess phenylalanine is toxic to the brain. Every piece of food that I give to my children to eat determines the health of their brain and their intellectual outcomes.
