Phenylketonuria in Children and Mothers

摘要

Phenylketonuria (PKU) is an inborn metabolicerror in which metabolism of phenylalanine into tyrosine isdisrupted. If the diet of an infant with PKU is not re-stricted, blood phenylalanine levels are elevated, leadingto irremediable brain damage and severe mental retar-dation. Children with PKU who are placed early andcontinuously on a low phenylalaninediet develop normallevels of intelligence, and brain damage is largely pre-vented. However, if the diet of a mother with PKU is un-restricted during her pregnancy, high phenylalanine levelsin her blood can cross the placental barrier and damagethe developing fetus in multiple ways. These results dem-onstrate how genes and environmental factors combine tocreate prenatal environments that can have profound ef-fects on the growth and development of offspring duringinfancy and childhood.