PKD explained for kids

“Pyru…what ???” A simple explanation for kids

What is Haemoglobin ?

Not enough Pyruvate Kinase



Yellow Skin

What is Haemoglobin ?

Your body is really a collection of  big and tiny factories. In those factories allot of different machines make very small, but useful products and because of all those tiny products, you and everybody else can live.

One of the big factories is your Bone Marrow. It might be weird to think about, but blood is made in your bones. A lot of tiny little, but very important cells that in the end will keep you safe, healthy and fit.

One of the blood cells is the Red blood cell, also called Haemoglobin. It’s an important cell that really acts like a truck. These trucks are very important because they transport the Oxygen that you breathe in. They are also very cool, because they are colorshifters, when the Oxygen goes in they are Bright red trucks, but when the Oxygen goes out they turn into Dark Red Trucks.  Anyway: all the air that you breathe in, is taken into the trucks and is being transported to all the cells in your body. Without the oxygen you wouldn’t be able to play, learn or dance so it’s a very important


 Not enough Pyruvate Kinase

In the disorder Pyruvate Kinase Deficiency one little factory called “The Empden Pathway factory” isn’t working properly. They are supposed to make parts for the door of the truck, but they don’t have the enough equipment to make it and so they make far to little of it.

So the product they are selling, which is Pyruvate Kinase, is not enough to make a good locking door . The Red blood cell might feel that something is off, but they have no other factory to go to, so they’ll take it anyway. There is a little bit of Pyruvate going into “the Glycolysis factory” which should make the door complete, but of course this can’t have a good outcome at all, because they didn’t have enough parts to work with.

So, now you know Pyruvate Kinase is used in making a door for the red truck. Without a good door everything you will put in the truck will get out and water might leak in when you are traveling.

That’s exactly what will happen to the red blood cell. The red truck starts their journey packed with Oxygen and other stuff. But the door will open very soon and a lot of stuff is getting in and out. However because the door wasn’t good enough the factory had come up with a little trick so the truck could deliver more oxygen then a normal truck would do and that will make things a bit easier.

After a while the truck comes at a crossing called Spleen. Here the truck will be checked over by lots of police agents and when it’s no good it will be destroyed. Off course they soon see that the truck is far from perfect and they will say: “You are not allowed to drive on the highway any longer, you will be destroyed.”

Because there are millions of red blood cells crossing this spleen it’s impossible to destroy everything thankfully , so a lot will get passed and move on with they’re journey.

Then they will pass a different station called the liver and again the red trucks, who will be getting really dark at that time,  will be inspected again by different police agents. And off course they will be firm again and say: Hey, you are not allowed to be on this high way, you need to be destroyed ! “And again a lot of trucks will be destroyed.

Like you have seen the oxygen will come out very soon, so the truck wants to go back as soon as possible to get some new oxygen. The trucks in your body will go superfast to bring it all around and get some new.

To get as much trucks on the road as possible, your bone marrow (remember this is the factory where the trucks were build) is working overtime. They make more and more red trucks. They work so hard that they even bring red trucks on the road that weren’t finished at all, but they are trying their best to do as much as they can.

Iron Overload

The spleen and the liver destroy more and more red trucks. And wha happens when you destroy a lot of trucks?  You will get a large scrap heap with a lot of stuff.

First there is allot of rubbish coming out of the red truck. Maybe you can see that as oil and petrol that is sticky and has to be destroyed. One of those waste products is called Bilirubin. It’s a yellow substance and your body is looking for a way to get rid of it. A lot of it will end up in the toilet. You might have seen that your urine is very dark sometimes? That is the Bilirubin. And whatever billi is left, will be stored in your body before that will be destroyed. Maybe you have seen the yellow coloring of your skin and eyes? Well that is bilirubin as well.

There is allot of Iron in a truck and in a different way also in your red blood cell. Not the same kind of iron and of course much smaller. But in the end, it is called iron (Ferritine). And this iron will have to go somewhere.  The spleen and the liver have produced some garbage trucks that will pick up all the iron and travel it to wherever they think it can be stored. A lot of it will end up in the toilet as well, but if it is too much, your body will put some in your muscles and in other places.

Maybe your doctor is giving you medicines to get rid of the iron. This medicine is really another garbage truck that will pick up all the iron that is stored somewhere and bring it right to the toilet where it belongs. So it is very important you take the medicine, because you will help your body a lot ! Next you can look at a Video of a young man explaining how he uses the Desferal pump he needs to get rid of his Iron:

Blood transfusions

When so much blood is being destroyed, sometimes your bone marrow can’t make enough red blood cells anymore to keep you fit and healthy. Or it works just hard and it needs a bit of a break. Then the doctor tells you that it is time to get a blood transfusion. But what is a blood transfusion?

A lot of people donate blood to a centre or what they call a blooddrive in some countries. They voluntarily let a nurse stick a needle in their veins to get blood. That’s awesome, isn’t it?   This blood will be collected and tested, because no one wants blood that will give you another disease of course.

In This Video you can see how a blooddonation works in the UK.

Photo: Magnetbox
Photo: Magnetbox/

After the blood is tested it will be stored in a very Cool environment; a very large freezer. There it will stay until the doctor will order it for you.

Then the blood is being transferred to the hospital that you are in and it will be thawed. You don’t want the icy blood after all. In the hospital the blood will be tested again, to see whether it will fit you right. You can see it as a puzzle. You are a big puzzle and you need a little piece of the puzzle that you’ve lost. The blood is the piece of the puzzle, but as you will understand this piece must fit into your puzzle otherwise it will not help you and mess everything up.

So, what the lab is really doing, is take a little bit of your blood and see if it will fit into the puzzle of the transfusion blood. If this is good, the blood will made ready for you.

Child with pyruvate kinase deficiency

Sometimes you might feel scared about all this. Maybe you really don’t like needles or maybe you don’t want to lose control. That’s very understandable. No one likes to be in the hospital or to have people sticking needles in you. And off course you know that you need it, but still….. Wat can you do about it ?

  • Talk about it with the people in the hospital.
  • Tell them how you feel, remember you are the patiënt but you are also the boss of your body.
  • If you really want the transfusion in the left or the right arm, tell them.
  • When you need some time before the needle is coming in, say it.
  • Speak up, that is the most important thing.
  • If you are scared about the blood, ask if you can look in the lab or let people explain to you how it all works. Never be afraid to ask, it’s your body and your pyruvate kinase deficiency, so you need to know everything.

Yellow skin

Some kids are being bullied because of the colour of their skin. Yellow isn’t really a popular colour and most kids see it as something weird and maybe scary. What should you do when this is happening to you?

The first thing that you should do is talk about it with someone you can trust. Ask advice and help.

Maybe it is a good idea to be very open about it. Tell the class what is wrong with your body and why you look the way you do. Sometimes children call you names because they are scarred, so tell them your story.

When it’s your turn to give a presentation in class, use your disease. You are the expert, so no teacher can give you a bad critic now. Maybe you can ask the hospital for some cool artefacts you can show.

Remember, You  ARE not the colour of your skin. Although it is on the outside and everybody can see it, you are so much more than that. Don’t hide yourself; You have a right to be on this world and you have been through so much already, be proud of yourself.

Drawing of yellow skin because of pyruvate kinase deficiency

Remember, although your body is different it’s also amazing. With all the rare issues going on in your body, you are stilling going strong. Again: be proud about what you already have achieved!

When you feel that you want to write something about what your experiences are or you have a question, please use the form below . We would really like to hear from you. Maybe it’s not you that has PKD but your sister, brother, mother or father. You are very welcome to write something to.

Disclaimer: This article is written by patients and is meant for basic informational purposes only. It is not intended to serve as medical advice, substitute for a doctor's appointment or to be used for diagnosing or treating a disease. Users of this website are advised to consult with their physician before making any decisions concerning their health. For details see our full disclaimer.