Description

Phenylketonuria (fen-ul-key-toe-NU-ree-uh), also known as PKU, is a rare hereditary disorder that causes an amino acid called phenylalanine to build up in the body. PHENYLKETONURIA (pku) is caused by a change in the phenylalanine hydroxylase (PAH) gene. This gene helps create the enzyme needed to break down phenylalanine.

Without the enzyme needed to break down phenylalanine, a dangerous buildup can develop when a person with PKU eats foods that contain protein or eat aspartame, an artificial sweetener. Eventually, this can lead to serious health problems.

For the rest of their lives, people with PKU — babies, children and adults need to follow a diet that limits phenylalanine, which is found mainly in foods that contain protein. New drugs may allow some people with PKU to eat a diet that has a higher or an unlimited amount of phenylalanine.

Babies in the united States and many other countries are screened for PKU soon after birth. Although there is no cure for PKU , recognizing the PKU and start treatment right away may help to prevent limitations in the areas of thinking, comprehension and communication (intellectual disabilities), and major health problems.

Symptoms

Newborns with PKU did not initially have no symptoms. However, without treatment, infants usually develop signs of the disease within a couple of months.

The signs and symptoms of PKU is not treated 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
  • The nervous system (neurological) problems may include seizures
  • Skin rashes, such as eczema
  • The clear skin, the hair and color of the eyes of the members of the family, because phenylalanine can't transform into melanin — the pigment responsible for hair and skin tone
  • Unusually small head size (microcephaly)
  • Hyperactivity
  • Intellectual disability
  • Developmental delay
  • Behaviour, emotional and social problems
  • Mental health disorders

The severity varies

The severity of this disease depends on the type.

  • ClassicPKU. The most severe form of the disease that is called classic PKU . The enzyme needed to break down phenylalanine is absent or very much reduced. This results in high levels of phenylalanine can cause serious brain damage.
  • Less severe forms ofPKU. In mild or moderate forms, the enzyme still has some function, so that the levels of phenylalanine are not as high, resulting in a lower risk of significant brain damage.

Regardless of the form, the majority of infants, children, and adults with this disorder require a special PKU diet to prevent intellectual disability and other complications.

Pregnancy and PHENYLKETONURIA

Women who have PKU and become pregnant are at risk of another form of the disease called PKU mothers . If the woman does not follow the special PKU diet before and during pregnancy, the levels of phenylalanine in the blood can be high and cause harm to the fetus.

Even the women with less severe forms of PKU may place the baby in her belly children at risk for non-compliance of the PKU diet.

Babies born to women with high levels of phenylalanine are usually not inherit PKU . But a child can have serious problems if the level of phenylalanine is high in the mother's blood during pregnancy. At birth, the baby may have:

  • Low birth weight
  • Unusually small head
  • Problems with the heart

In addition, the PKU breast can cause that the child has developmental delay, intellectual disability, and behavior problems.

When to see a doctor

Talk with your health care provider in these situations:

  • Newborns. If the routine screening of the newborn shows that your baby may have PKU , your child's healthcare provider will want to start a diet treatment immediately to avoid long-term problems.
  • In women of reproductive age. It is especially important for women with a history of PKU to see a health care provider and maintain the PKU diet before you get pregnant and during pregnancy. This reduces the risk of high blood phenylalanine levels of damage to their babies before birth.
  • To the adults. People with PKU need to receive care for life. Adults with PKU who have left the FCU of the diet in adolescence may benefit from a visit with their health care providers. Returning to the diet may improve mental function and behavior, and prevent further damage in the central nervous system that can be the result of high levels of phenylalanine.

Causes

A change in the gene (gene mutation) causes PHENYLKETONURIA , which can be mild, moderate, or severe. In a person with PKU , a change in the phenylalanine hydroxylase (PAH) gene responsible for the lack or reduction of the amount of the enzyme needed to process phenylalanine, an amino acid.

A dangerous build-up of phenylalanine can develop when a person with PKU eats foods rich in protein, such as milk, cheese, nuts or meat, or grains such as bread and pasta, or aspartame, an artificial sweetener.

The inheritance

For a child to inherit PKU , the father and the mother must have and pass on the mutated gene. This pattern of inheritance is called autosomal recessive inheritance.

It is possible for a father to be a carrier of the mutation that causes PKU , but do not have the disease. If only one parent has the mutated gene, there is no risk of passing PKU to a child, but it is possible that the child will be a carrier.

Most often, the PHENYLKETONURIA (pku) is passed to children by two parents who are carriers of the mutation, but do not know it.

Risk factors

Risk factors for the inheritance of PKU include:

  • Having both parents with a change in the gene that causesPKU. Both parents must pass along a copy of the altered gene for their child to develop the condition.
  • Being of a certain race or ethnic heritage. PKU affects people of most ethnicities from all around the world. But in the united States, it is more common in people of European ancestry, and less common in people of African descent.

Complications

Untreated PKU can lead to complications in babies, children and adults with the disorder. When women with PKU have high levels of phenylalanine in the blood during pregnancy can harm your unborn baby.

Untreated PKU can lead to:

  • Irreversible brain damage and marked intellectual disability onset within the first months of life
  • Neurological problems such as seizures and tremors
  • Behavioural, emotional and social problems in older children and adults
  • The main problems of health and development

Prevention

If you have PHENYLKETONURIA (pku) and is considering the possibility of getting pregnant:

  • Follow a diet low in phenylalanine. Women with PKU can prevent damage to your developing baby to stay or return to a low-phenylalanine diet before you get pregnant. Nutritional supplements are designed for people with PKU can ensure the sufficient amount of protein and nutrition during pregnancy. If you have PHENYLKETONURIA (pku), talk with your health care provider before you start trying to conceive.
  • Consider the possibility of genetic counselling. If you have PHENYLKETONURIA (pku), a close relative with PKU or a child with PKU , you may benefit from genetic counseling before you get pregnant. A specialist in medical genetics (genetic counselor) can help you to better understand how to PHENYLKETONURIA (pku) is passed through your family. The specialist can also help you determine your risk of having a child with PKU and help with the planning of the family.

Diagnosis

Newborn screening identifies almost all cases of phenylketonuria. All 50 states of the usa require newborns to be screened for PKU . Many other countries also routinely screen infants for PKU .

If you have PHENYLKETONURIA (pku) or a family history of the same, your doctor may recommend screening tests before pregnancy or at birth. It is possible to identify the PKU carriers through a blood test.

The evidence of your baby after birth

A PKU test is done a day or two after the birth of your baby. To obtain accurate results, the test is performed after the baby is 24 hours old and after your baby has had quite a bit of protein in the diet.

  • A nurse or a lab technician collects a few drops of blood from your baby's heel.
  • A laboratory testing of the blood sample to certain metabolic disorders, including PHENYLKETONURIA (pku).
  • If you do not deliver your baby in a hospital or are discharged shortly after birth, you may need to schedule an evaluation of newborns with your health care provider.

If this test shows that your baby may have PKU :

  • Your baby may have additional tests to confirm the diagnosis, including blood tests and urine analysis
  • You and your baby can have genetic testing to identify the change in the gene for PHENYLKETONURIA

Treatment

Starting treatment early and continuous treatment throughout life can help prevent intellectual disability and major health problems.

The main treatments for PKU include:

  • The whole life of the diet with very low intake of foods with phenylalanine
  • Taking a PKU special formula of nutritional supplement for all of life to make sure they get enough essential protein (without phenylalanine) and nutrients that are essential for growth and general health
  • Medications for certain people with PKU

A safe amount of phenylalanine is different for each person with PKU and may vary over time. In general, the idea is to consume only the amount of phenylalanine that is necessary for healthy growth and processes of the body, but no more. Your health care provider can determine a safe amount through:

  • Periodic review of the records of food and growth charts
  • Frequent blood tests to monitor the levels of phenylalanine in the blood, especially during childhood growth spurts and pregnancy
  • Other tests that evaluate the growth, development and health

Your doctor may refer you to a registered dietitian who can help you learn about the PKU diet, make adjustments to your diet where needed, and offer suggestions on how to manage the PKU diet challenges.

Which foods and products to avoid

Due to the amount of phenylalanine that a person with PKU can eat is so low, it is important to avoid all foods that are rich in protein, such as:

  • Milk
  • Eggs
  • Cheese
  • Nuts
  • Soy products, such as soybeans, tofu, tempeh, and milk
  • Beans and peas
  • Poultry, beef, pork and other meat
  • Fish

Potatoes, cereals and other vegetables, it will probably be limited.

Children and adults should also avoid other foods and beverages, including many diet sodas and other drinks that contain aspartame (NutraSweet, Equal). Aspartame is an artificial sweetener made with phenylalanine.

Some products may contain aspartame, and some vitamins or other supplements may contain amino acids or fat-free milk powder. Check with your pharmacist about the content of the otc products and prescription drugs.

Talk with your doctor or dietitian to learn more about your diet.

Formula for people with PKU

Due to the restriction of the diet, people with PKU need to get the essential nutrients through a special nutritional supplement. The phenylalanine-free formula provides essential proteins (amino acids) and other nutrients in a form that is safe for people with PHENYLKETONURIA .

Your health care provider and dietitian can help you find the right type of formula.

  • Formula for infants and young children. Because regular infant formula and breast milk contain phenylalanine, infants with PKU in place you need to have a phenylalanine-free formula. A dietitian can carefully calculate the amount of breast milk or regular formula is to be added to the phenylalanine-free formula. The dietitian can also teach parents how to choose the solid foods while not going over the child's daily, the phenylalanine of the grant.
  • The formula for the older kids and adults. Older children and adults continue to drink or eat a phenylalanine-free nutritional supplement (protein equivalent of the formula), as directed by a doctor or dietician. Your daily dose of the formula is divided among his meals and snacks, instead of being eaten or drunk all the time. The formula for older children and adults is not the same as the one used for babies, but also provides an essential protein without phenylalanine. The formula is the continuation of life.

The need of a nutritional supplement, especially if you or your child does not find it attractive, and the limited selection of food can make the PKU diet challenging. But making a firm commitment to this lifestyle change is the only way to avoid the serious health problems that people with PKU can develop.

PKU medicine

The Food and Drug Administration (FDA) approved the drug this medicine (Kuvan) for the treatment of PKU . The drug can be used in combination with a PKU diet. Some people with PKU who are taking the medication does not need to follow a PKU diet. But the drug does not work for everyone with PKU .

The FDA also approved a novel enzyme therapy, pegvaliase-pqpz (Palynziq), for adults with PKU when the current therapy does not respond properly to reduce the level of phenylalanine. But due to the frequency of side effects, which can be severe, this treatment is only available as part of a restricted program under the supervision of certified health care providers.

Lifestyle and home remedies

Strategies to help manage PKU include monitoring the food that you eat, measuring properly, and be creative. Like anything, the more these strategies are practiced, the greater the comfort and confidence that you can develop.

Maintain a tracking and to measure properly

If you or your child is following a low-phenylalanine diet, you need to keep records of the food we eat every day.

To be as accurate as possible, measure the portions of food using the standard measuring cups and spoons, and a kitchen scale that reads in grams. Amounts of food are compared with a list of foods or are used to calculate the amount of phenylalanine to eat every day. Each meal and snack includes properly the part of your daily PKU formula.

Food diaries, computer programs and smart phone apps are available the list of the amount of phenylalanine in the baby food, solid foods, PKU formulas, and common baking and cooking ingredients.

Meal planning or meal rotations of the most well-known of the food may help to reduce some of the daily follow-up.

Be creative

Talk with your dietitian to find out how you can get creative with meals to help you stay on track. For example, the use of condiments, and a variety of cooking methods to transform the bottom of the phenylalanine vegetables in a menu of different dishes. Herbs and spices, low in phenylalanine can have a lot of flavor. Just remember to measure and count all of the ingredients and adjust the recipes to your specific diet.

If you have any other health conditions, you may also need to consider those when you plan your diet. Talk with your doctor or dietitian if you have any questions.

Coping and support

Living with PKU can be a challenge. These strategies can help:

  • Stay informed. Know the facts about PKU can help you take charge of the situation. Discuss any questions with your pediatrician, family doctor, a geneticist, or a dietitian. Read books and cook books written specifically for people with PHENYLKETONURIA .
  • Learn from other families. Ask your health care provider about local or online support groups for people living with PKU . Talking with others who have mastered similar challenges that can be useful. The National PKU Alliance is an online support group for families and adults with PKU .
  • Get help with planning the menu. A dietitian with experience in the PKU can help you to design delicious low-phenylalanine dinners. Your dietitian can also have great ideas for meals, parties and birthdays.
  • Plan ahead when dining out. A meal at the local restaurant gives you a break from the kitchen and it can be fun for the whole family. Most places offer something that fits in the PKU diet. But you may want to call and ask any questions about the menu or bring food from home.
  • Find sources of financial aid. Ask your health care provider or dietitian if there are programs or plans of insurance that helps cover the high costs of the formula and low protein foods. Also, to see if your school lunch program will make adjustments for special dietary needs.
  • Don't focus on the food. By the time of the food on the family time can take some of the look of the food. Try the conversations with the family or playing games, while eating. Encourage the children with PKU to focus on sports, music, or hobbies, not only in what they can and can't eat. Also consider the possibility of creating christmas traditions that center on special projects and activities, not just the food.
  • Let your child help you manage the diet as soon as possible. Young children can make decisions about what to cereal, fruit or vegetables they like to eat and help measure the portions. They can also help to pre-measured snacks. Older children can help with the planning of the menu, pack your own lunches and keep your own record of the power supply.
  • Make your grocery list and the meals with the whole family in mind. A cupboard full of food-restricted it may be tempting to a child or an adult with PKU , so try to focus on foods that everyone can eat. Serve the stir-fried vegetables that are low in protein. If the other members of the family you want, you can add the peas, corn, meat, and rice. Or set up a salad bar with a low-protein and moderate-protein options. You can also serve the whole family for a delicious low in phenylalanine, soup, or curry.
  • Be prepared for potlucks, picnics, and trips in the car. Plan ahead, so there is always a PKU-friendly food option. Package of snacks of fresh fruit or a lower content of proteins cookies. Take fruit skewers or kebabs of vegetables for a meal in the open air, and make a low-phenylalanine salad to the neighborhood of the food. Other parents, friends, and family members is likely to make adjustments and be helpful if you explain the dietary restrictions.
  • Talk with teachers and other staff of the school of your child. Your child's teachers and cafeteria staff can be a big help with the PKU diet if you take the time to explain its importance and how it works. Working with teachers of your child, you can also plan for the future for the special school of parties and events for your child to have always a delight to eat.

Preparing for your appointment

Pku is usually diagnosed through newborn screening. Once your child is diagnosed with PKU , it is likely that you will have to be referred to a medical center or specialty clinic with a specialist who treats PKU and a dietitian with experience in the PKU diet.

Here's some information to help you prepare for your appointment and know what to expect.

What you can do

Before your appointment:

  • Ask a family member or friend to go to the appointment with you — sometimes it can be difficult to remember all the information provided during an appointment.
  • Make a list of questions to ask your health care provider and nutritionist to help you make the most of their time together.

Some questions may include:

  • How did my child get the PKU ?
  • How do we manage PKU ?
  • Are there medications for the treatment of this disorder?
  • What foods are completely off limits?
  • What is the recommended diet?
  • My child have to stay in this special diet for life?
  • What type of formula will my child need? Can my child have breast milk?
  • There are other supplements necessary?
  • What happens if my child eat a food that he or she is not supposed to eat?
  • If I have another child, that child has PKU ?
  • Are there brochures or other printed material I can have? What sites do you recommend?

What to expect from your doctor

Your health care provider is likely to ask several questions. For example:

  • Has your child had any of the symptoms that concern you?
  • Do you have any questions about your child's diet?
  • Do you have any difficulty following the diet?
  • The growth and development of your child (a) typical of other children of the same age?
  • Have you ever had genetic testing?
  • Do any other family members have PKU ?

Your doctor will ask additional questions based on your responses, symptoms, and needs. Prepare and anticipate the questions will help you make the most of your appointment time.

Symptoms and treatment of Phenylketonuria (PKU)