How does a gene cause Wilson’s disease?

Wilson’s disease happens when a gene change stops the liver removing excess copper.

The gene that causes Wilson’s disease is called ATP7B.

This gene tells your liver how to make a protein that helps the body remove copper.

People with Wilson’s disease have a changed version of this gene. This is like having a spelling mistake in the instructions for making the protein. It means the liver cannot make the protein properly.

The changed version of the gene is called a variant version or variant gene. You might also hear it called a gene fault, or gene mutation.

We know about more than 2,700 different variants of the Wilson’s gene. Researchers know that at least 800 of these cause the condition. But there are likely more that we have not found yet.

Some variants are more common in certain parts of the world.

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How is Wilson’s disease inherited?

Wilson’s disease only happens if you inherit two variant versions of the Wilson’s gene.

We all have 2 copies of every gene. We get one from each of our biological parents.

Most people inherit 2 normal copies of the Wilson’s gene. So they will not develop Wilson’s disease.

Wilson’s disease only happens when someone inherits 2 changed or variant copies of the Wilson’s gene. You might hear this type of inherited condition called an autosomal recessive condition.

Carriers

If someone inherits just one variant copy of the Wilson’s gene, their liver can use their other, working copy. They will not have Wilson’s disease. But they could pass on the variant gene. This is called being a carrier.

About 1 in 40 people are carriers of Wilson’s disease.

You will not get Wilson’s disease if:

• You have one working and one variant Wilson’s gene (you are a carrier)
• You have 2 working copies of the Wilson’s gene.

Not everyone with the genes for Wilson’s disease will develop the condition

It is thought that only about 1 in 4 people who have the genes for Wilson’s disease will develop the condition. We do not yet fully understand why some people with the genes get Wilson’s disease and others do not.

Doctors sometimes talk about “gene penetrance” this is difference between the number of people with the genes for a condition and the how many of them actually have the condition.

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What are the chances my children will get Wilson’s disease?

If you have Wilson’s disease, you will pass on the gene for it to your children. But they will only get the condition if they inherit a variant of the Wilson’s gene from both parents. And even if they have two variant versions, they might not get the condition.

Overall, if you have Wilson’s disease, the chance of your child also getting it is less than 1 in 100.

The risk is higher if you and your partner are blood relatives (like cousins). This is because you are more likely to have similar genes.

Which genes we pass on is random. We have no control over which genes we get from our parents. Or over which copy of each gene we pass on to our children.

If you are thinking about starting a family, talk to your Wilson’s team and ask for a referral to a genetic counsellor. They will be able to talk to you about the chances of passing on the condition. They can also tell you about tests and help you to decide if these would be a good option for you.

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Examples: How children inherit Wilson’s disease 

If I have Wilson’s disease, will my children get it?

If I am a carrier for Wilson’s disease will my children get it?

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Who else should have tests for Wilson’s disease?

If someone has Wilson’s disease, it is important for close family members to have tests too.

Early detection of Wilson’s disease allows treatment to begin before serious damage occurs to the liver or brain. This may mean starting treatment before there are any symptoms of the condition.

Close family members who should have tests are:

• brothers and sisters
• children

Sometimes testing is also offered to cousins.

Find out more about testing for family members.

Find out more about genetic and inherited liver conditions

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Useful words – genetic terms explained

ATP7B  – The gene that can cause Wilson’s disease
Autosomal recessive – how some genetic conditions pass from one generation to the next. You need to inherit a variant gene from both parents to get the condition.
Carrier – Someone who has one variant copy and one working copy of the Wilson’s gene. A carrier doesn’t have the condition, but there’s a chance they could pass it on to their children.
Gene – A part of your DNA that gives your body instructions. You have two copies of each gene, one from each parent.
Gene penetrance – The difference between how many people have the genes for a condition and how many actually get the condition.
Genetic testing – A test that looks for specific changes in a gene or genes.
Variant gene – A gene that has changed in some way. This might also be called a changed, mutant, or faulty gene.