Early detection and adherence to a strict dietary regimen have prevented much of the intellectual disability that used to occur in those with phenylketonuria (PKU). Affected individuals now often lead normal lives and have families. For various reasons, such individuals tend to adhere less rigorously to their diet as they get older. Predict the effect that mothers with PKU who neglect their diets might have on newborns.

Verified step by step guidance

1. Understand that phenylketonuria (PKU) is a genetic disorder caused by a deficiency in the enzyme phenylalanine hydroxylase, leading to the accumulation of phenylalanine in the body.
2. Recognize that high levels of phenylalanine are toxic to the brain and can cause intellectual disabilities if not managed through a strict diet low in phenylalanine.
3. Consider that during pregnancy, a mother with PKU who does not adhere to her dietary restrictions can have elevated levels of phenylalanine in her blood.
4. Realize that high maternal phenylalanine levels can cross the placenta and affect the developing fetus, potentially leading to congenital disabilities and intellectual disabilities in the newborn, a condition known as maternal PKU syndrome.
5. Conclude that it is crucial for mothers with PKU to maintain a strict diet before and during pregnancy to prevent adverse effects on their newborns.

Key Concepts

Phenylketonuria (PKU)

Phenylketonuria (PKU) is a genetic disorder caused by a deficiency in the enzyme phenylalanine hydroxylase, which is necessary for metabolizing the amino acid phenylalanine. When individuals with PKU consume foods high in phenylalanine, it accumulates in the body, leading to severe neurological damage and intellectual disabilities if not managed through a strict low-phenylalanine diet.

Maternal PKU and Teratogenic Effects

Maternal PKU refers to the condition where a woman with PKU becomes pregnant and does not adhere to her dietary restrictions. High levels of phenylalanine during pregnancy can cross the placenta, potentially leading to teratogenic effects on the developing fetus, including cognitive impairments, growth deficiencies, and other serious health issues.

Dietary Management and Long-term Outcomes

Dietary management in PKU involves strict adherence to a low-phenylalanine diet, especially during critical periods such as pregnancy. Failure to maintain this diet can result in elevated phenylalanine levels, which can adversely affect both the mother's health and the newborn's development, leading to increased risks of intellectual disabilities and other complications.