TEMPLE. Tools Enabling Metabolic Parents LEarning ADAPTED BY THE DIETITIANS GROUP. British Inherited Metabolic Diseases Group

TEMPLE Tools Enabling Metabolic Parents LEarning ADAPTED BY THE DIETITIANS GROUP British Inherited Metabolic Diseases Group BASED ON THE ORIGINAL TEMPLE WRITTEN BY BURGARD AND WENDEL

PKU Information for families following a positive newborn screening ADAPTED BY THE DIETITIANS GROUP British Inherited Metabolic Diseases Group BASED ON THE ORIGINAL TEMPLE WRITTEN BY BURGARD AND WENDEL TEMPLE Tools Enabling Metabolic Parents LEarning

What is PKU? PKU stands for Phenylketonuria. It is pronounced fee-nile-keto-nurea. It is an inherited metabolic condition. Phenyl keto nuria PKU 1

What is PKU? Too many Phenylketones in the urine Too much phenylalanine in the blood 2

PKU and protein PKU affects the way your baby breaks down protein. Many foods contain protein. The body needs protein for growth and repair. 3

What is protein? A M I A C I N D O S 4

Protein and enzymes Protein is broken down into amino acids (building blocks of protein) by enzymes (which are like chemical scissors). Enzymes then further break the amino acids into smaller parts or chemicals. 5

Protein metabolism Metabolism refers to the chemical processes that occur inside the cells of the body. Anabolism Catabolism 6

What happens in PKU? PKU is caused by a deficiency of an enzyme called phenylalanine hydroxylase. This results in the amino acid, phenylalanine, not being broken down, so instead it builds up in the blood and brain. Blood tyrosine levels are low and phenylketones are found in the urine. Phe Tyr Phe Tyr 7

What can go wrong in PKU? Without management, over time, the build-up of phenylalanine causes irreversible brain damage and poor intellectual development. With management the outcome is good. 8

What about other symptoms? If blood levels of phenylalanine are poorly controlled, it is likely to lead to learning difficulties and behaviour problems. 9

How is PKU diagnosed? 10

How is PKU managed day to day? Avoidance of high protein foods Avoidance of aspartame A phenylalanine restricted diet using protein exchanges Prescribable phe-free protein substitute and low protein foods 11

Foods to avoid These foods are rich in protein and therefore phenylalanine and must be avoided: meat, fish, eggs, cheese, milk, bread, pasta, nuts, soya, Quorn and tofu. Any food or drink containing aspartame should also be avoided. 12

Phenylalanine exchanges Phenylalanine is essential for normal development and therefore a limited and controlled amount must be taken daily. 1 exchange equals the amount of food that provides 50mg phenylalanine or 1g protein. 1 exchange = 50mg phe = 1g protein These foods must be weighed or measured to ensure the correct amount is given. 80g 35g 13 20g

Phenylalanine exchanges Breast milk or standard infant formula will provide the phenylalanine required by your baby for at least the first 17 weeks. The amount given will be monitored regularly by your specialist metabolic dietitian. 14

Phenylalanine-free protein substitute Phenylalanine-free protein substitute is essential to meet your baby s nutritional requirements. The Phenylalanine-free protein substitute is prescribable. 15

Phe-free foods for PKU These are foods that contain small quantities of phenylalanine which can be used in normal quantities. They include fruits, many vegetables and prescribable low protein foods such as bread and pasta. They provide: an important source of energy variety in the diet 16

Low protein cooking 17

How is PKU monitored? By regular blood spots taken by you at home and sent to the local screening laboratory The sample is tested for the amount of phenylalanine it contains The metabolic dietitian will contact you with the result and discuss any changes in management 18

How is PKU managed during illness? During any childhood illness, catabolism or protein breakdown occurs, causing blood phenylalanine levels to increase. It is important to continue with the usual diet as much as possible. Glucose polymer and the phenylalanine free protein substitute can help control blood phe levels. 19

How is PKU managed during illness? Continue Phenylalanine in food and drink Protein substitute should be given with all illnesses Glucose polymer powder provides energy during illness 20

What happens at PKU clinic? Height and weight Diet is adjusted according to growth and blood tests Developmental check Blood tests for amino acid and nutrient levels 21

Chromosomes, genes, mutations Humans have chromosomes composed of DNA. Genes are pieces of DNA that carry the genetic instruction. Each chromosome may have several thousand genes. The word mutation means a change or error in the genetic instruction. We inherit particular chromosomes from the egg of the mother and sperm of the father. The genes on those chromosomes carry the instruction that determines characteristics, which are a combination of the parents. 22

Inheritance PKU is an inherited condition. There is nothing that could have been done to prevent your child from having PKU. Everyone has a pair of genes that make the phenylalanine hydroxylase enzyme. In children with PKU, neither of these genes works correctly. These children inherit one non-working PKU gene from each parent. Parents of children with PKU are carriers of the condition. Carriers do not have PKU because the other gene of this pair is working correctly. 23

Inheritance Autosomal-recessive (carriers of PKU) Mother is a carrier of PKU Father is a carrier of PKU Female egg cells Male sperm cells 24

Inheritance Autosomal recessive possible combinations Mother is a carrier of PKU Father is a carrier of PKU Child will not be a carrier of PKU Child will be a carrier of PKU Child will have PKU 25

Future pregnancies When both parents are carriers, in each pregnancy the risk to the baby is as follows: 25% chance (1 in 4) of PKU 50% chance (1 in 2) for the baby to be a carrier of PKU 25% chance (1 in 4) for the baby to have two working genes and neither have PKU or be a carrier 26

Take home messages PKU is a serious inherited, metabolic disorder. Damage can be prevented with a diet low in phenylalanine and a special protein substitute. Remember to always give the correct amount of phenylalanine (exchanges) and protein substitute as prescribed by your metabolic centre. Regular blood spot tests are essential to monitor blood phenylalanine levels. 27

Helpful hints Always ensure you have a good supply of your special dietary products and phenylalanine free protein substitute and that they are in date. Your special dietary products and phenylalanine free protein substitute are prescribed by your GP and you will obtain them from the pharmacy (community or hospital) or via home delivery. Always ensure you have sufficient blood testing equipment and to send samples on a regular basis. Medications to control fever should be given as normally recommended always keep supplies available. 28

Who s who My dietitians My nurses My doctors Contact details, address, photos 29

Visit www.lowproteinconnect.com and register to get access to support and practical advice for those living on a low protein diet. The site also provides information on upcoming events and personal stories from others on a low protein diet. British Inherited Metabolic Diseases Group www.bimdg.org.uk www.nutricia.co.uk www.nspku.org www.pku.ie