What happens if phenylketonuria is not treated

Those of Irish heritage as well as those with Turkish background have the highest risk.. Before signs are apparent, however, the brain may already be damaged, so treatment needs to begin during the first weeks of life before this happens Symptoms of PKU can include:. If treatment is administered within the first few weeks after birth, there should be no symptoms if the diet that is prescribed is strictly followed. Symptoms might develop if the patient stops following the diet.

A: PKU is very serious if treatment is not started for within the first 2 to 3 weeks of life. Although symptoms may not be visible, exposure to high levels of phenylalanine after 2 to 3 weeks can have long lasting negative effects such as intellectual challenges.

Untreated PKU can lead to intellectual disabilities. If PKU is treated right away and your child strictly follows the prescribed low-phenylalanine diet, your child should enjoy a normal quality of life. A: If a woman with PKU is not following a strict low phenylalanine diet during pregnancy, her baby may suffer from intellectual disabilities, heart defects and a small head microcephaly , even though her baby may not inherit PKU.

Women looking to become mothers should follow a low-phenylalanine diet beginning before pregnancy to prevent their baby from suffering from PKU in the mother.

A: The main treatment for PKU is following a strict diet that eliminates high protein food such as, meat and dairy products and introduces a special formula. We will work with you and your child to establish a diet he can be on for life. A: If your child follows the diet correctly to get all the nutrients he needs, there should not be any side effects.

A: The answer depends on who your child has a baby with. PKU is a recessive disease, meaning that the child with PKU gets two abnormal genes, one from each parent. If your child has a baby with someone who does not have a PKU gene has two normal genes none of the babies will have PKU. Following the strict diet can be difficult, and may lead to stress and anxiety. If it is followed correctly there should not be any physical effects on the body. The PKU diet is complicated and hard to manage.

As a result, the severe signs and symptoms of classic PKU are rarely seen. Mutations in the PAH gene cause phenylketonuria. The PAH gene provides instructions for making an enzyme called phenylalanine hydroxylase. This enzyme converts the amino acid phenylalanine to other important compounds in the body.

If gene mutations reduce the activity of phenylalanine hydroxylase, phenylalanine from the diet is not processed effectively. As a result, this amino acid can build up to toxic levels in the blood and other tissues. Because nerve cells in the brain are particularly sensitive to phenylalanine levels, excessive amounts of this substance can cause brain damage. Classic PKU, the most severe form of the disorder, occurs when phenylalanine hydroxylase activity is severely reduced or absent.

People with untreated classic PKU have levels of phenylalanine high enough to cause severe brain damage and other serious health problems. Mutations in the PAH gene that allow the enzyme to retain some activity result in milder versions of this condition, such as variant PKU or non-PKU hyperphenylalaninemia.

Changes in other genes may influence the severity of PKU, but little is known about these additional genetic factors. This condition is inherited in an autosomal recessive pattern , which means both copies of the gene in each cell have mutations.

The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition. Genetics Home Reference has merged with MedlinePlus. Learn more. The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health. From Genetics Home Reference. Description Phenylketonuria commonly known as PKU is an inherited disorder that increases the levels of a substance called phenylalanine in the blood.

Frequency The occurrence of PKU varies among ethnic groups and geographic regions worldwide. This pattern of inheritance is called autosomal recessive. It's possible for a parent to be a carrier — to have the defective gene that causes PKU, but not have the disease.

If only one parent has the defective gene, there's no risk of passing PKU to a child, but it's possible for the child to be a carrier. Most often, PKU is passed to children by two parents who are carriers of the disorder, but don't know it. Untreated PKU can lead to complications in infants, children and adults with the disorder.

When mothers with PKU have high blood phenylalanine levels during pregnancy, fetal birth defects or miscarriage can occur. Mayo Clinic does not endorse companies or products. Advertising revenue supports our not-for-profit mission. This content does not have an English version. This content does not have an Arabic version.

Overview Phenylketonuria fen-ul-key-toe-NU-ree-uh , also called PKU, is a rare inherited disorder that causes an amino acid called phenylalanine to build up in the body. Email address. First Name let us know your preferred name.

Last Name. Thank you for subscribing Your in-depth digestive health guide will be in your inbox shortly. Sorry something went wrong with your subscription Please, try again in a couple of minutes Retry. Request an Appointment at Mayo Clinic. Autosomal recessive inheritance pattern Open pop-up dialog box Close. Autosomal recessive inheritance pattern To have an autosomal recessive disorder, you inherit two mutated genes, one from each parent.

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