Children with PKU cannot use part of protein called Phenylalanine (Phe) if left untreated, Phe builds up in the body and can cause brain damage. However this condition is easy managed by following a special diet and people with PKU can still live normal lives and go on to have successful careers, go to university and enjoy a happy family life like everyone else.
How Did Amelia Get PKU?
As a parent to a child with PKU both Me and my husband have one PKU gene and one normal gene. This is known as being a carrier. Your body then chooses which gene is passed on when conceiving a baby, Amelia inherited 2 PKU genes - one from me and one from her dad.
Around 1 in 50 people carry the PKU gene and would never know that they were carriers until two people with this gene conceive a baby with PKU. Once me and Lawrence decided to have a baby there was 1 in 4 chance that our child would get PKU.
The Science of PKU
We all need protein to help build, repair and maintain body cells and tissues, like skin, muscles, organs, blood and bones.
When protein is eaten, it is broken down in the body (during digestion) into smaller pieces called amino acids. There are 20 amino acids that make up protein. Some of these are essential and cannot be made in the body so they must come from the food we eat. Phenylalanine (Phe) is one of these. It is this particular amino acid that Amelia cannot process properly because of PKU.
Normally the liver produces an enzyme called phenylalanine hydroxylase. This enzyme breaks down Phenylalanine (Phe) to another chemical called Tyrosine (Tyr) which is important for many functions in the body. In a person that has PKU this process does not happen as it should... The phenylalanine hydroxylase is not made by the liver or the enzyme does not work properly. This means phenylalanine (Phe) is not converted to Tyrosine (Tyr) and builds up in the blood. This is the reason for a special diet to be followed. So there is too much Phenylalanine (Phe) and not enough Tyrosine (Tyr) which can cause problems. Therefore there is a need for extra Tyrosine (Tyr) in Amelia's diet.
The Special Diet
- Phenylalanine (Phe) is found in all protein containing foods (meat, milk, eggs etc)
- In order to manage PKU all protein foods must be restricted - and a low protein/Phe diet must be followed
- All amino acids have a role or function in the body. Phenylalanine (Phe) helps us with our growth, development and tissue repair.
- It is important that someone with PKU gets some Phenylalanine (Phe) but not so much that it becomes harmful.
Following the traffic light system and knowing which colour a food falls under is key.
- Red (meat, pasta, cheese, bread, fish etc) are not allowed as these are too high in protein/Phe.
- Amber (potatoes, peas, rice, frozen chips etc) contain small amounts of protein. They would need to be eaten in measured amounts - these amounts vary from person to person as each person has a different level of tolerance to protein/Phe.
- Green (fruit, vegetables, sugar etc) are naturally low in protein so are good to have.
Also people like Amelia with PKU will get special foods which have been specially made to be low in protein so special bread, pasta, cake etc are available when Amelia is older.
Monitoring
This condition needs monitoring from an early age which means Amelia has to have weekly blood spot tests to check her Phenylalanine levels and going to the children's hospital in Bristol 3 times a year. She will have a dietitian for life and as she grows up she will be referred to different people to help with her development. Both me and Lawrence will be trained to do her blood spot tests and eventually so will Amelia.
So follow our journey as we learn more about Phenylketonuria (PKU) and follow Amelia's development and learn about her special diet with us...
