Phenylketonuria (PKU) And the Need For Good Nutrition

PKU is a genetic, metabolic disorder which prevents the body from oxidizing phenylalanine hydroxylase. As this chemical continues to build up, mental retardation, sometimes severe, may result, with very few of those with untreated PKU having an IQ over 50. It is important to have a low protein diet, the only way to remove the excess phenylalanine from the blood, and this diet should be started as early as possible to minimize the risk of mental retardation.

Testing for PKU is required for all newborn babies in the United States, as well as for those in other countries. Because of this testing and the ability to start treatment from an early age, there have been many people with PKU who have grown up and gone on to have children of their own. However, these women have to be careful to continue following the low-protein diet so that they do not put their children at risk for a number of serious conditions, including mental retardation, congenital heart disease, facial abnormalities and microcephaly (a small skull which is associated with retardation as well) (Source: Sarason and Sarason 2005)

There are usually no symptoms for the newborn baby with PKU, but they will develop them within a few months if there is no treatment. Some of these can include mental retardation, behavioral or social problems, seizures, tremors or jerking movements, usually in the arms and legs, hyperactivity, stunted growth, skin rashes, small head size (also called microcephaly) and a musty odor that is noted in the child’s breath, skin or urine, which is a result of too much of the amino acid phenylalanine. The child normally has fair skin and blue eyes because the phenylalanine is not able to transform into melanin, which is needed for darker hair and skin tone.

It is believed that the low-protein diet can be stopped once the child hits his teen years, however, this is not always true over the lifetime. A woman who is pregnant may have to go back to the low-protein diet to protect her unborn baby. Most babies born to PKU mothers do not inherit the disease themselves. Some doctors suggest that the diet be followed for the entire lifetime regardless. Each doctor will make a decision based on the individual patient rather than making a blanket decision.

Because this is a genetic disorder, it is important to know as much about your genetic history so that you will be aware of the risk factors. One parent can be a carrier but not have the actual disease, which will then cause the baby to be born with PKU. If only one person has the gene, then there is no risk for passing PKU on.

PKU is more common in those who are of Northern European or Native American ancestry and is less common in African Americans, Asians and Hispanics. (Source: Mayo Clinic)

When Alison and Jacob found out that they were going to have a baby, they were thrilled. However, after a check of their family background, they found out that they both have the defective gene responsible for PKU, meaning that their baby has a bigger chance of inheriting this rare, metabolic disorder. During their pregnancy, they study all of the information that they can get their hands on and consider whether or not they want to screen the baby before he is born, giving them additional time to get ready, or to wait until the birth to find out if he has PKU or not.

Allison is nervous and decides to have a test for PKU using chorionic villus sampling to test for PKU and a number of other conditions. For this test, a needle is inserted into the uterus through the abdomen or up through the cervix. A small sample is collected and then tested. If the baby does have PKU, the doctor will suggest genetic counseling and education.

The diet that the baby will have to follow will start with special formula until he is ready to be weaned. As he grows, he will also have to work to avoid certain common foods, which include milk, eggs and cheese, nuts, soybeans, beans, chicken, beef, fish, chocolate, peas and foods made with asparatame, an artificial sweetener which is found in a number of products like diet soft drinks and some medications. Other foods may also need to be limited, including pasta, rice, bread, cookies and some fruits and vegetables. The foods that are allowed should not be eaten too much either.

Allison is shocked to learn that she will not be able to breastfeed her baby either, because breast milk will also contain phenylalanine from the mother’s diet. She may be able to give him a small amount of breast milk because of the health benefits. As the baby gets older, he may be given a different formula as a supplement to his diet.

He may also need to have some low-protein substitutes of foods that resemble what others are eating – but these foods can be very expensive and may be available only in limited places.

The dietician will give Allison and Jacob several recipes to follow for the baby’s meals, including ways to eat healthy foods that are still low in protein. The couple knows they will have to pay careful attention to labels so that their baby stays as healthy as he possibly can. In addition to dealing with this condition, they have to deal with the higher cost of the care of their child, such as his meds and his meals.

It is important that Allison and Jacob get emotional support wherever they can, so they join an online PKU support group so that they can get advice and tips from families that are in the same position. They also like the idea of sharing their own advice with others as well. They work with a registered dietician who will help to guide them through the different stages in their baby’s life. Once a week, they will leave their baby with Allison’s mother who knows and understands the diet so they can go out and eat a “normal” meal without worrying about the restrictions and limits.

One of the couple’s concerns is school time. When the baby is old enough to go to school, Allison is worried about school lunches: will the school be able to accommodate the baby’s needs? What if he is trading lunches with other students once he gets there?

Both Allison and Jacob are also concerned about their own health. While the baby is going to need to follow a very low-protein diet, neither of them should, so while they will be eating much of the same foods as the baby, they will also both be using a protein supplement called Profect, from Protica, so that they can maintain their own strength and health status. They will get 25 grams of protein per serving and they can consume each in a matter of seconds as a between-meal snack. It is available in a number of different flavors so they do not have to stick with the same taste over and over.

This entry was posted in Uncategorized. Bookmark the permalink.