what is the possibility that pku is passed on

Causes

PKU is passed on to children when each parent has 1 mutated gene. This means that neither parent has any symptoms of PKU, but both are carriers of the faulty gene. PKU is an autosomal recessive disease.

Symptoms

PKU is caused by a defect in a gene known as the PAH gene. This defect changes the way that phenylalanine is broken down by the body during digestion. PKU is passed on to children when each parent has 1 mutated gene. This means that neither parent has any symptoms of PKU, but both are carriers of the faulty gene.

Prevention

The disorder is passed down in a recessive pattern, which means that for a child to develop PKU, both parents have to contribute a mutated version of the PAH gene. If both parents have PKU, their child will have PKU as well.

Complications

High levels of Phe can permanently damage the nervous system and brain, causing a variety of health problems. These include seizures, psychiatric problems, and severe intellectual disability. PKU is caused by a genetic mutation, a change in the normal function of a gene.

How is PKU passed on to children?

What is PKU and what causes PKU?

Is PKU recessive or dominant?

What are the long term effects of PKU?

What is the possibility of PKU being passed on?

If only one parent has the changed 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 both carriers of the changed gene, but don't know it.

Can phenylketonuria be passed down?

How PKU is inherited. The genetic cause (mutation) responsible for PKU is passed on by the parents, who are usually carriers and do not have any symptoms of the condition themselves. The way this mutation is passed on is known as autosomal recessive inheritance.

What is the probability of producing a child with PKU?

When both parents are carriers of the faulty PKU gene, their child will be born with PKU if they receive one copy of the faulty gene from each parent. When both parents are carriers, the possibilities in each pregnancy are: 1 in 4 chance of having an affected child. 2 in 4 chance of having a child that is a carrier.

What is the percent chance of having a child who is a carrier for PKU but does not have PKU?

1-in-2 chance (50 percent) that your baby won't have PKU but will be a PKU carrier.

Who is most likely to get PKU?

These can include genes with mutations or changes that can cause PKU. 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.

What gender is PKU most common in?

Contexts in source publication ... 377 adult individuals with PKU were identified, resulting in a period prevalence of 10.13 in 2015 (per 100,000 individuals). Most adult PKU patients were female (58.1%) and the mean age of adult PKU patients in 2015 was 50.9 ± 20.4 years ( Table 1). ...

What is the probability of having a normal child?

The Punnett square below makes it clear that at each birth, there will be a 25% chance of you having a normal homozygous (AA) child, a 50% chance of a healthy heterozygous (Aa) carrier child like you and your mate, and a 25% chance of a homozygous recessive (aa) child who probably will eventually die from this ...

Can people with PKU have kids?

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.

How many babies are born PKU?

In the United States, about 1 in 10,000 to 15,000 babies is born with PKU each year. The illness happens in all ethnic groups.

How long is the average lifespan of a person with PKU?

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.

Can PKU cause autism?

In the group of 35 patients diagnosed late, two boys (5.71%) ages 16 and 13 years fulfilled the diagnostic criteria for autism. The present study confirms that classical PKU is one of the causes of autism, but the prevalence seems to be very low.

Is PKU life long?

Your phenylketonuria (PKU) diagnosis is lifelong, so stay up to date with your healthcare provider and get routine blood tests to monitor the level of phenylalanine in your body. If you are on a restricted diet, you still need to eat foods and take vitamins to make up for the lack of protein in your diet.

Does PKU run in families?

PKU is inherited from a person's parents. The disorder is passed down in a recessive pattern, which means that for a child to develop PKU, both parents have to contribute a mutated version of the PAH gene.

How do you prevent phenylketonuria?

Can phenylketonuria be prevented or avoided? Because PKU is a genetic condition, it can't be prevented or avoided. Genetic testing is the only way to determine if people carry the defective gene.

What happens if PKU is left untreated?

Children with PKU who are not treated may develop symptoms including behavioral problems, seizures, and severe intellectual and developmental disabilities. Adults with PKU who do not follow a special diet may develop unstable moods2 and take longer to process information.

How common is PKU in newborns?

Without treatment, phenylalanine builds up in the blood and causes health problems. In the United States, about 1 in 10,000 to 15,000 babies is born with PKU each year. The illness happens in all ethnic groups.

What is the cause of PKU?

PKU is caused by mutations in the gene that helps make an enzyme called phenylalanine hydroxylase (pronounced fen-l-AL-uh-neen hahy-DROK-suh-leys ), or PAH. This enzyme is needed to convert the amino acid phenylalanine into other substances the body needs. When this gene, known as the PAH gene, is defective, the body cannot break down phenylalanine.

What does it mean when a parent does not have a PKU?

Sometimes, a parent does not have PKU but is a carrier, which means the parent carries a mutated PAH gene. If only one parent carries the mutated gene, the child will not develop PKU.

What is the chance of a child having a PKU?

If both of a child's parents are carriers, there is a 25% chance that each parent will pass on the normal PAH gene. In this case, the child will not have the disorder. Conversely, there also is a 25% chance that the carrier parents will both pass along the mutated gene, causing the child to have PKU. However, there is a 50% chance that a child will inherit one normal gene from one parent and one abnormal one from the other, making the child a carrier.

Does phenylalanine harm nerve cells?

Amino acids help build protein, but phenylalanine can cause harm when it builds up in a person's body. In particular, nerve cells in the brain are sensitive to phenylalanine.

Is PKU inherited?

PKU is inherited from a person's parents. The disorder is passed down in a recessive pattern, which means that for a child to develop PKU, both parents have to contribute a mutated version of the PAH gene. If both parents have PKU, their child will have PKU as well.

What causes PKU?

A defective gene (genetic mutation) causes PKU, which can be mild, moderate or severe. In a person with PKU, this defective gene causes a lack of or deficiency of the enzyme that's needed to process phenylalanine, an amino acid. A dangerous buildup of phenylalanine can develop when a person with PKU eats protein-rich foods, such as milk, cheese, ...

What is the most severe form of PKU?

The severity of PKU depends on the type. Classic PKU. The most severe form of the disorder is called classic PKU. The enzyme needed to convert phenylalanine is missing or severely reduced, resulting in high levels of phenylalanine and severe brain damage. Less severe forms of PKU.

Why is it important to maintain a PKU diet?

It's especially important for women with a history of PKU to see a doctor and maintain the PKU diet before becoming pregnant and during pregnancy to reduce the risk of high blood phenylalanine levels harming their unborn babies. Adults. People with PKU continue to receive care across the life span.

What foods can cause phenylalanine buildup?

A dangerous buildup of phenylalanine can develop when a person with PKU eats protein-rich foods, such as milk, cheese, nuts or meat, and even grains such as bread and pasta, or eats aspartame, an artificial sweetener. This buildup of phenylalanine results in damage to nerve cells in the brain.

What is the name of the condition where a defect in the gene causes phenylalanine to build up?

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. PKU is caused by a defect in the gene that helps create the enzyme needed to break down phenylalanine.

How do you know if you have a PKU?

However, without treatment, babies usually develop signs of PKU within a few months. PKU signs and symptoms can be mild or severe and may include: A musty odor in the breath, skin or urine, caused by too much phenylalanine in the body.

Why do children with PKU need special diets?

But most children with the disorder still require a special PKU diet to prevent intellectual disability and other complications.

What happens if you eat PKU?

If you have PKU and eat these foods, Phe will build up in the blood. High levels of Phe can permanently damage the nervous system and brain, causing a variety of health problems. These include seizures, psychiatric problems, and severe intellectual disability.

What happens during a PKU screening test?

A health care provider will clean your baby's heel with alcohol and poke the heel with a small needle. The provider will collect a few drops of blood and put a bandage on the site.

What is a PKU screening test?

A PKU screening test is a blood test given to newborns 24–72 hours after birth. PKU stands for phenylketonuria, a rare disorder that prevents the body from properly breaking down a substance called phenylalanine (Phe). Phe is part of proteins that are found in many foods and in an artificial sweetener called aspartame.

What is a PKU diet?

A PKU diet usually means avoiding high-protein foods such as meat, fish, eggs, dairy, nuts, and beans. Instead, the diet will probably include cereals, starches, fruits, a milk substitute, and other items with low or no Phe.

When do you have to get a PKU test?

If the results were normal, but the test was done sooner than 24 hours after birth, your baby may need to be tested again at 1 to 2 weeks of age. Learn more about laboratory tests, reference ranges, and understanding results.

Do you need a PKU test for a newborn?

Newborns in the United States are required to get a PKU test . A PKU test is usually part of a series of tests called a newborn screening. Some older infants and children may need testing if they were adopted from another country, and/or if they have any symptoms of PKU, which include: Delayed development.

Do you have to pass a PKU test?

For a child to get the disorder, both the mother and father must pass down a mutated PKU gene. Although PKU is rare, all newborns in the United States are required to get a PKU test. The test is easy, with virtually no health risk.

What is a PKU?

Symptoms of PKU range from mild to severe. Severe PKU is called classic PKU. Infants born with classic PKU appear normal for the first few months after birth. However, without treatment with a low-phenylalanine diet, these infants will develop mental retardation and behavioral problems.

How is PKU diagnosed?

PKU is usually diagnosed through newborn screening testing that is done shortly after birth on a blood sample (heel stick). However, PKU should be considered at any age in a person who has developmental delays or mental retardation. This is because, rarely, infants are missed by newborn screening programs.

What is phenylketonuria (PKU)?

Phenylketonuria (PKU) is an inherited disorder of metabolism that causes an increase in the blood of a chemical known as phenylalanine. Phenylalanine comes from a person's diet and is used by the body to make proteins. Phenylalanine is found in all food proteins and in some artificial sweeteners. Without dietary treatment, phenylalanine can build up to harmful levels in the body, causing mental retardation and other serious problems.

What are the symptoms of PKU?

Infants born with classic PKU appear normal for the first few months after birth. However, without treatment with a low-phenylalanine diet, these infants will develop mental retardation and behavioral problems. Other common symptoms of untreated classic PKU include seizures, developmental delay, and autism. Boys and girls who have classic PKU may also have eczema of the skin and lighter skin and hair than their family members who do not have PKU.

What is the treatment for PKU?

PKU is treated by limiting the amount of protein (that contains phenylalanine) in the diet. Treatment also includes using special medical foods as well as special low-protein foods and taking vitamins and minerals. People who have PKU need to follow this diet for their lifetime. It is especially important for women who have PKU to follow the diet throughout their childbearing years.

What is PKU in medical terms?

What is phenylketonuria (PKU)? Phenylketonuria (PKU) is an inherited disorder of metabolism that causes an increase in the blood of a chemical known as phenylalanine. Phenylalanine comes from a person's diet and is used by the body to make proteins.

What is a baby born with mild PKU?

Babies born with less severe forms of PKU (moderate or mild PKU) may have a milder degree of mental retardation unless treated with the special diet. If the baby has only a very slight degree of PKU, often called mild hyperphenylalaninemia, there may be no problems and the special dietary treatment may not be needed.

Why is PKU administered?

It is administered to newborns in order to test for phenylketonuria and is a mandatory screening in all 50 states of the US. PKU is a condition that has a highly likelihood of causing brain damage and intellectual disabilities when left untreated. Children with PKU can have a difficult time eating and may develop a rash that looks similar to eczema.

What happens if you miss a PKU blood test?

If the PKU blood test was missed for some reason, then there is also a urine test that can be conducted to determine if the genetic disorder may be present. In the past, there weren’t many actions that could be taken to help treat children with this genetic disorder.

What About Mothers Who Have PKU?

For mothers who are trying to become pregnant or have a confirmed pregnancy, a PKU blood test may also be ordered to determine what her phenylalanine levels happen to be. Even if a child does not have the inherited disorder themselves, a mother’s high levels of phenylalanine can still cause brain damage and/or intellectual deficits in the child after birth.

What is PKU in food?

PKU is an inherited condition that forces individuals with it to avoid phenylalanine consumption. It’s found in many foods and requires an enzyme to break it down. People with PKU don’t have this enzyme, so phenylalanine levels can build up and cause damage. The links to brain damage and PKU has been known since 1930 and is ...

How much phenylalanine is in blood?

In general, however, the normal levels of phenylalanine that are in the blood are less than 2 mg/dL. When a blood test result comes back as having more than 4 mg/dL, or double the normal amount, then the medical provider will suspect that PKU may be present and recommend a treatment protocol.

How long does it take for a PKU to be detected?

Most hospitals or medical providers will have the PKU blood test happen within the first 2 days of life. The newborn’s heal will be pricked so that the blood test can be conducted. It is then sent to a lab to determine if PKU is present.

Can you test for PKU at birth?

This diet will then be extended to other foods once a child is able to chew. Some countries do not screen for PKU at birth, so parents who are adopting children from other nations may need to have a PKU blood test conducted to determine if the condition is present.

How is PKU caused?

PKU is caused by a defect in a gene known as the PAH gene. This defect changes the way that phenylalanine is broken down by the body during digestion. PKU is passed on to children when each parent has 1 mutated gene. This means that neither parent has any symptoms of PKU, but both are carriers of the faulty gene.

Why is PKU important?

It helps the body make protein. It's also important for brain growth. It's normally changed to tyrosine, which helps create all of the body's proteins. But with PKU, the amino acid can build up in the bloodstream and cause harm. PKU is found with a simple blood test. All newborn babies in the U.S. are screened for PKU.

What is phenylketonuria (PKU) in children?

Phenylketonuria (PKU) is a rare metabolic disorder. Children with PKU can’t process an amino acid called phenylalanine. Phenylalanine is in many common foods. It helps the body make protein. It's also important for brain growth. It's normally changed to tyrosine, which helps create all of the body's proteins. But with PKU, the amino acid can build up in the bloodstream and cause harm. PKU is found with a simple blood test. All newborn babies in the U.S. are screened for PKU.

What are the symptoms of PKU in a child?

If a baby is not tested and has undiagnosed PKU, he or she may show signs or symptoms at several months old. Some babies with PKU may seem more drowsy and listless than normal. They may have feeding problems. As they continue to take in protein and phenylalanine through their diets, they may have growth, mood, behavior, and thinking problems, as well as other problems. Symptoms can range from mild to severe based on how much phenylalanine is in the blood.

How is PKU diagnosed in a child?

All newborn babies in the U.S. are screened for PKU with a blood test. If you adopt a child from another country, he or she may need to be screened for PKU and other genetic diseases.

What are possible complications of PKU in a child?

This can cause low birth weight, slow growth, small head, behavior problems, and heart disorders. These mothers are also at risk for pregnancy loss.

How can I help prevent PKU in my child?

Women with PKU who are of childbearing age should be careful to follow a strict low-protein diet. Your healthcare provider may advise genetic counseling. You can discuss with a counselor the risk for PKU in a future pregnancy.

Overview

Symptoms

Causes

Risk Factors

Complications

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Prevention