Phenylketonuria, commonly referred to as PKU, is a rare metabolic disorder. People with PKU cannot metabolize phenylalanine (Phe), an amino acid found in all kinds of dietary protein. If untreated, Phe builds up in the blood and tissues to levels causing irreversible brain damage and neurological complications including IQ loss, memory loss, seizures, learning disabilities, and emotional problems.
PKU can be diagnosed at birth and is commonly included in newborn screening programs in most high-income countries. All PKU affected newborns must immediately begin to follow a very strict, lifelong, low-protein diet. Consequently, people with PKU must abstain from eating high-protein food such as meat and fish, cheese and milk, beans and peas, egg, bread and pasta.
The burden of living with PKU to both individuals and society is immense. Many adults affected by PKU reduce their working hours, and parents report quitting their job to take care of a child with PKU. Cooking is complicated due to the dietary restrictions, and the special foods modified to be low in protein available to children and adults with PKU are expensive.
Travelling and dining out – activities which to most people are unproblematic – require substantial planning. And due to the stigma of not being able to eat a normal mealy with friends and family, eating disorders and food phobias are well-known side-effects of PUK, particularly amongst adolescent patients.