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Tyrosinemia type II

Tyrosinemia type II affects the way the body breaks down an amino acid called tyrosin. Children with tyrosinemia type II can experience symptoms, including redness and pain of the eye, excessive tears in the eye, sensitivity to light and thick, painful skin on the palms of their hands and the bottoms of their feet. Babies with condition can often be treated and usually life a healthy and normal life, if the condition is known about at birth or shortly after. About half of the people affected with tyrosinemia type II can have some sort of intellectual disability, but early management of the condition can reduce this risk.

Quick facts about tyrosinemia type II
Genes: TAT
Inheritance: Autosomal Recessive
Relevant resources for tyrosinemia type II

A quick genetics rundown

As humans we have about 23,000 genes. These genes are like tiny instruction manuals that influence our health, growth and development. We inherit half of our genes from our biological mum and the other half from our biological dad. These genes are lined up on structures called chromosomes. Most of us have 23 pairs of chromosomes. The first 22 pairs are called autosomes and for the most part - these are the same among men and women. The 23rd pair determine our sex - two X chromosomes for a female and one X and one Y chromosome for males.

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How is tyrosinemia type II inherited?

tyrosinemia type II is known as an autosomal recessive condition. For autosomal recessive conditions, if a person has a variation in one copy of their gene, they are a carrier. This means that they are healthy because they also have a working copy of the gene. But, they can still pass their non-working copy to their child.

If the other parent also happens to be a carrier of the same gene, there is a 25% (1 in 4) chance that they both pass this gene variation on to their child — and as such, have a child affected by the condition.

If both parents are carriers of tyrosinemia type II, there's a one in four chance that their children could develop symptoms.

What is carrier screening?

Carrier testing is like a checkup for your genes. It tests to see if you carry a gene variation that could cause a serious genetic condition in your child. Eugene offers an inclusive genetic carrier screening panel that includes tyrosinemia type II, but there's a total 301 conditions that can be tested.

Eugene's carrier test is a clinical grade test that can be done from the comfort of your own home — it's just a saliva test. You're also paired with a genetic counsellor who provides mindful support and guidance every step of the way.

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Should parents screen for tyrosinemia type II before or early in pregnancy?

The biggest benefit of screening for tyrosinemia type II is that it can help future parents understand their reproductive risk so they can be ready and empowered to make more informed decisions. If neither partner are carriers, it provides reassurance and peace of mind that the risk of having a child with a genetic condition is low.

Since 90% of children that have a recessive genetic condition like tyrosinemia type II had no previous family history of it, it often feels completely out of the blue for the parents. Getting screened is a way to know this risk in advance, which can help familes manage or even prevent the condition in the first place.