"...Autism is linked to certain medical conditions, including fragile X syndrome, untreated phenylketonuria (PKU), tuberous sclerosis, and congenital rubella syndrome..."

"...People with phenylketonuria must not supplement phenylalanine..."

"...Known causes of seizures include ... Metabolic abnormalities found in diabetes mellitus, electrolyte imbalances, kidney failure, uremia, nutritional deficiencies and phenylketonuria (PKU)..."