PKU affects the brain. High blood Phe levels can cause disruptions in neurotransmitters like serotonin and dopamine, which are important for mood, learning, memory, and motivation. In addition to disrupting neurotransmitter balance, Phe itself can be directly toxic to the brain.

1) deficiency. PAH is a liver-specific enzyme that catalyses the hydroxylation of l-phenylalanine (Phe) to l-tyrosine in the presence of the cofactor, tetrahydrobiopterin. Accumulation of phenylalanine generates a brain damage and consequently irreversible mental retardation.

Untreated PKU can lead to: Irreversible brain damage and marked intellectual disability beginning within the first few months of life. Neurological problems such as seizures and tremors. Behavioral, emotional and social problems in older children and adults.

The psychiatric symptoms and developmental delay being reported in PKU patients could be explained by many mechanisms, such as, myelin abnormalities, defect in the amino acids transport through blood–brain barrier, and reduction of some neurotransmitters levels (dopamine, norepinephrine, and serotonin).

PKU does not shorten life expectancy, with or without treatment. Newborn screening for PKU is required in all 50 states. PKU is usually identified by newborn screening. A child’s outlook is very good if she strictly follows the diet.

After all, PKU is a rare, genetic disorder of amino acid metabolism identified at birth by pediatricians and treated by geneticists. But, PKU is also a disorder that, if left untreated, leads to severe behavioral difficulties and ultimately mental retardation.

In the United States, PKU is most common in people of European or Native American ancestry. It is much less common among people of African, Hispanic, or Asian ancestry.

There currently is no cure for PKU, but the condition is controllable through proper diet and supplements.

This is consistent with the recent findings of the systematic review by Medford (2017) including 29 articles representing 1784 PKU patients of all ages, who found that the main factor associated with worsening of metabolic control was age [9], as well as a less recent retrospective chart review related to 125 PKU …

A person with PKU does not outgrow it and must stay on the diet for life.

If PKU is confirmed, treatment will be given straight away to reduce the risk of serious complications. Treatment includes a special diet and regular blood tests. With early diagnosis and the correct treatment, most children with PKU are able to live healthy lives.

Problems experienced by children with PKU were: difficulty with maintaining focus (48%, n = 114/236), educational difficulties (28%, n = 67/236), anxiety or depression (29%, n = 68/236), and gastrointestinal symptoms (34%, n = 97/282).

Ask the healthcare provider what the test results mean for your child. The test screens for blood levels of phenylalanine. Normal levels of phenylalanine in the blood are less than 2 milligrams per deciliter (mg/dL). More than 4 mg/dL of phenylalanine in the blood is considered high and may mean your child has PKU.

As PKU is inherited in an autosomal recessive fashion, all children of a mother with PKU will inherit 1 affected gene.

PKU is passed down through families. For a baby to have the disease, he or she must get (inherit) the PKU gene from both parents. The father and mother may not have PKU or even know that PKU runs in their families.

Pregnancy and Phenylketonuria (PKU) Girls or women with PKU can have healthy children as long as they are aware of and maintain strict adherence to their low phenylalanine diet throughout their pregnancy.

Children with PKU have lower levels of melanin, the substance that gives color to hair and skin. That’s because when phenylalanine is broken down, one of its products is used to make melanin. As a result, children with PKU often will have pale skin, blond hair and blue eyes.

When two carriers conceive a child, there is a one in four (or 25%) chance for each pregnancy that the baby will have PKU. The incidence of carriers in the general population is approximately one in fifty people, but the chance that two carriers will mate is only one in 2500[2].

In the United States, about 1 in 10,000 to 15,000 babies is born with PKU each year.