galactosemia
As part of the Galactosemia community, we're on this journey together. Let's help one another find our way forward.
What is Galactosemia?
Galactose builds up in the blood because the body cannot process this simple sugar.
Take a closer look
There's more to the story about how Galactosemia affects the body.
When everything is working the way it should, galactose is converted by Pathway #1. In this pathway, galactose is turned into galactose-1-phosphate, or Gal-1p by the GALK enzyme.
Because of the inactive or missing GALT enzyme, Gal-1p can't be processed any further. Gal-1p clogs the pathway, so galactose can't go where it's supposed to.
Backed-up galactose overflows into Pathway #2, where it shouldn't go. An enzyme that's not supposed to be involved—Aldose Reductase—changes galactose into toxic galactitol.
There's more to the story about how Galactosemia affects the body.
Words to Know In Galactosemia
Making the Connection
In Galactosemia, galactose is mistakenly turned into a substance called galactitol. Galactitol is highly toxic, which means it's harmful to the body.
Toxic galactitol can build up in the blood, tissues, and organs, including the brain. There is evidence that toxic galactitol is responsible for a range of health issues that people with Galactosemia may experience.
Rare and Different
Galactosemia is a rare condition that is diagnosed in approximately 80 newborns in the U.S. each year. In total, it affects 3,000 people in the U.S.
There are several types of Galactosemia. And while each person's experience with Galactosemia will be unique, there are some similar characteristics between each different type.
Testimonials
This is galactose. It's a kind of sugar.
Galactose is found in milk, dairy products, and other foods.
Your child's body also makes galactose on its own, even if they never eat anything with galactose in it. In fact, every cell of the human body produces galactose from birth through adulthood.
Galactosemia is a condition in which the body has trouble processing galactose.
To understand why this happens, we need to look at metabolic pathways. These are chemical reactions that convert molecules in the body.
When everything is normal and working the way it should, galactose is converted by a specific pathway that we'll call Pathway #1. In this pathway, galactose is turned into galactose-1-phosphate, or Gal-1p for short.
People with Galactosemia are missing a key enzyme called GALT, so Gal-1p can't be processed any further. Instead, Gal-1p backs up and clogs the pathway, so galactose can't go where it's supposed to. Testing for high levels of Gal-1p is how we currently monitor Galactosemia.
But Galactosemia is a tale of two pathways. We've learned that when galactose backs up with nowhere to go it overflows into a different metabolic pathway, where it shouldn't go. We'll call it Pathway #2.
Galactose travels along Pathway #2, but the pathway doesn't normally have what it takes to process galactose. An enzyme in Pathway #2 that's not supposed to be involved converts the galactose. This enzyme is called Aldose Reductase. It changes galactose into galactitol.
Galactitol is highly toxic. This means it's harmful to the body. Galactitol can build up in the blood, tissues, and organs, including the brain.
There is evidence that toxic galactitol is responsible for a range of health problems that people with Galactosemia may experience, such as speech issues, cognitive delays, fertility issues in girls, seizures and tremor.
Currently, a diet that cuts out galactose is the only tool we have to manage the condition. But because the body makes galactose on its own, diet alone isn't enough.