Stevenson was sentenced to four years in prison for managing prostitutes and assault, but was released after 20 months. S tevenson was enraged by the La Presse story, though I have yet to find a press account in which he actually denied the details.
Genetic mutation. PKU is caused by a genetic mutation (change to the DNA) in the human phenylalanine hydroxylase (PAH) gene. There are many different types of mutations that can affect the PAH gene, all of which result in the body not producing a functioning PAH enzyme.
People with untreated classic PKU have levels of phenylalanine high enough to cause severe brain damage and other serious medical problems. Mutations in the PAH gene that allow the enzyme to retain some activity result in milder versions of this condition, such as variant PKU or non-PKU hyperphenylalaninemia.henylketonuria-caused by mutations in the PAH gene. More than 500 mutations in the PAH gene have been identified in people with phenylketonuria (PKU). Most of these mutations change single amino acids in phenylalanine hydroxylase.