What can be done to prevent the disease?

The genetic defect causing PKU cannot be prevented. If the defect is detected early in life, an individual can follow a special diet low in phenylalanine. This will prevent the mental retardation and learning disabilities.

What are the long-term effects of the disease?

If treatment is started early in life, there are few long-term effects. Otherwise, affected persons may have serious learning disabilities. They may also die at a young age.

What are the risks to others?

Phenylketonuria is not contagious. However, a person with PKU will pass on an abnormal gene to his or her children. The children will not be affected, however, unless the other parent also has the abnormal gene. Parents who have a child with phenylketonuria are at risk for having other affected children. Genetic counseling can be helpful in this situation.

A woman with phenylketonuria must take special care during pregnancy. If she is on a regular diet, the enzyme defect may cause her unborn child to be severely affected. She will need to follow a special diet low in phenylalanine during pregnancy.