Is there a critical period for PKU?

Phenylketonuria (PKU) is a genetically inherited disorder that, left untreated, changes cells inside the brain and leads into mental retardation. This dramatic change in behavior can be traced to a tiny mutation on a single gene on chromosome 12. Once detected the newborn child can be treated with a special diet to prevent the disease from reaching it’s potential.

Prior to birth there is another possibility. The critical period from conception till birth. A women with PKU can also give her child a PKU-like condition during pregnancy, but has nothing to do with what genes the child has. The fetus will feel the effect of her mother’s phenylalanine level if it is high even when the child has a normal PAH gene. Once born the child may have cognitive delays, heart disease, and/or a smaller than usual brain.

Submitted by: John Mansolf

2/19/02