Phenylketonuria (PKU) is a treatable disorder that affects the way the body processes protein. Children with PKU cannot use a part of the protein called phenylalanine. If left untreated, phenylalanine builds up in the bloodstream and causes brain damage.

How does phenylketonuria affect everyday life?

PKU leads to a build-up of the amino acid phenylalanine, which is toxic to the nervous system. Without treatment, PKU can cause intellectual disabilities. PKU does not shorten life expectancy, with or without treatment. Newborn screening for PKU is required in all 50 states.

Who does phenylketonuria affect the most?

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.

How does phenylketonuria affect physical development?

The developing baby in the uterus can be exposed to very high levels of phenylalanine. This can cause low birth weight, slow growth, small head, behavior problems, and heart disorders.

What happens when phenylalanine accumulates in the body?

Phenylalanine is an essential nutrient, but some individuals are born with a genetic disorder, phenylketonuria (PKU), that prevents them from metabolizing phenylalanine, and, if untreated, phenylalanine accumulates in the body, becomes converted into phenylpyruvate, and the individual usually develops seizures, brain ...

Phenylketonuria - causes, symptoms, diagnosis, treatment, pathology

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What organs does phenylketonuria affect?

A. In a child with PKU, phenylalanine cannot be converted to tyrosine because the phenylalanine hydroxylase enzyme does not work properly. This results in dangerously high levels of phenylalanine that build up in the blood and become toxic to the brain and nervous system.

Does phenylketonuria cause brain damage?

Without treatment, PKU can damage the brain and nervous system, which can lead to learning disabilities. Other symptoms of untreated PKU include: behavioural difficulties such as frequent temper tantrums and episodes of self-harm.

Why do people with phenylketonuria have light skin?

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.

Why is phenylalanine bad for you?

Phenylalanine can cause intellectual disabilities, brain damage, seizures and other problems in people with PKU . Phenylalanine occurs naturally in many protein-rich foods, such as milk, eggs and meat. Phenylalanine is also sold as a dietary supplement.

What are the side effects of phenylalanine?

Side effects may include:

• Heartburn.
• Fatigue.
• Nausea.
• Constipation.
• Dizziness.
• Headache.
• Anxiety and hypomania (a milder form of mania)
• Sedation.

Do black people get PKU?

The good news is that early treatment can prevent all or most problems. Babies born with PKU need to start treatment with special formula soon after birth. PKU is more common in whites and Native Americans than in blacks, Hispanics, and Asians.

What gender is PKU most common in?

Each year 10,000 to 15,000 babies are born with the disease in the United States and Phenylketonuria occurs in both males and females of all ethnic backgrounds (although it is more common in individuals of Northern European and Native American heritage.)

What foods should be avoided with PKU?

PKU diets typically do not contain high-protein foods such as:

• Meat, eggs, and fish.
• Bread, noodles, and wheat products.
• Nuts, peas, and beans (and products made from these foods).
• Milk and cheese.
• Chocolate.

How long do you live with phenylketonuria?

The average age at death was 55.8 years. Eleven subjects were still alive (seven females and four males). The oldest living male was 79 years of age. The average age of the survivors was 55.7 years.

Can phenylketonuria be cured?

There currently is no cure for PKU, but the condition is controllable through proper diet and supplements. What kinds of diets do children with PKU need to adopt? PKU is caused by the body's inability to metabolize phenylalanine, which is found in high protein foods such as poultry, meat, eggs and dairy products.

Can you get PKU later in life?

Although it is principally a childhood disorder, in rare cases, the first signs of PKU may develop in late adulthood resembling common neurological diseases.

Is phenylalanine bad for your liver?

Phenylalanine is thought to mediate or exacerbate hepatic encephalopathy, and an impaired liver may not be able to cope with the ammoniagenic properties of the amino acid constituents, or adequately metabolize methanol.

Does phenylalanine raise blood pressure?

Phenylalanine can increase a chemical in the body called tyramine. Large amounts of tyramine can cause high blood pressure.

Does phenylalanine cause anxiety?

DL-phenylalanine may cause symptoms of anxiety, jitteriness, and hyperactivity in children. Doses higher than 5,000 mg a day may be toxic and can cause nerve damage. High quantities of DL-phenylalanine may cause mild side effects such as nausea, heartburn, and headaches.

Can PKU cause hair loss?

10 Fair skin and hair resulting from impairment of melanin synthesis is the most characteristic cutaneous manifestation of PKU. 67 Patients often have typical pigmentation, light sensitivity, increased incidence of pyogenic infections, increased incidence of keratosis pilaris, hair loss, and eczema.

How is PKU detected?

Newborn blood testing identifies almost all cases of phenylketonuria. All 50 states in the United States require newborns to be screened for PKU. Many other countries also routinely screen infants for PKU. If you have PKU or a family history of it, your doctor may recommend screening tests before pregnancy or birth.

Why is phenylalanine bad for the brain?

As seen later in the literature study, phenylalanine may cross the blood–brain barrier and cause severe changes in the production of very important neurotransmitters. Methanol breaks down into formate, which in turn is very cytotoxic and can even cause blindness.

Why does PKU cause mental retardation?

Mutations in the PAH gene can cause phenylketonuria (PKU), a disorder that can change cells in the brain. The faulty protein allows dangerously high levels of phenylalanine to accumulate in the brain, poisoning the cells. If a person with PKU consumes too much phenylalanine, the build-up can cause mental retardation.

Why does PKU cause neurological symptoms?

PKU affects the brain.

When neurotransmitters are not made in the right amounts, the brain cannot function properly. High blood Phe levels can cause disruptions in neurotransmitters like serotonin and dopamine, which are important for mood, learning, memory, and motivation.

What is Tay Sachs syndrome?

Tay-Sachs disease is a rare inherited condition that mainly affects babies and young children. It stops the nerves working properly and is usually fatal. It used to be most common in people of Ashkenazi Jewish descent (most Jewish people in the UK), but many cases now occur in people from other ethnic backgrounds.