Reproductive Options for People With XLH

If you and/or your partner have X-linked hypophosphatemia (XLH), you may worry about the potential risks involved with pregnancy or that you will pass on the disease to your children. However, there are several reproductive options and tests available to help you plan and and make the best decisions for you and your family.

How is XLH inherited?

XLH is an X-linked dominant genetic disorder. This means people with a mutation in the PHEX gene that resides on the X chromosome will have the disease whether they are male or female.

Males inherit one X chromosome from their mother and one Y chromosome from their father. Females, on the other hand, inherit an X chromosome from both parents. Because of this, if the father has XLH, none of his sons will have XLH, but all of his daughters will inherit it.

If the mother has XLH, any of her children have a 50% chance of inheriting the disorder. If both partners have XLH, all their daughters will have the disease, and their sons will have a 50% chance of inheriting the disease.

It is important to note that roughly 20–30% of XLH cases are due to mutations that occurred during the formation of egg and sperm cells. In these instances, neither parent has XLH.

Can XLH affect my pregnancy?

Women with XLH can still become pregnant. However, there may be a higher risk of some complications. These may include fetal growth restriction and preeclampsia. Studies have also shown that women with XLH are more likely to deliver via a Cesarean section. This is mostly due to patient and physician choice because of concerns over the risk of obstruction during a vaginal delivery due to the small stature and narrowed birth canals of the mother.

If you are planning to expand your family and either you or your partner have XLH, you should discuss your options for pregnancy and genetic testing with your physician and a genetic counselor.

Genetic testing

You can choose to genetically test your children before they are born. This is called prenatal genetic diagnosis. Here, the doctor takes a sample from the fetus in the early stages of the pregnancy to check for any errors in the DNA that could result in a genetic disorder such as XLH.

Amniocentesis and chorionic villus sampling (CVS) are the two techniques commonly used to obtain the sample from the fetus.

In amniocentesis, the doctor inserts a long needle through the mother’s abdomen and into the amniotic sac to take a sample of the amniotic fluid. This is the fluid that surrounds the fetus. It contains cells from the fetus that clinicians can use for genetic testing.

CVS involves taking samples of the placenta, which supplies blood and nutrients to the fetus. The placenta contains the genetic material of the mother and the baby.

In vitro fertilization

Using in vitro fertilization (IVF) and testing the embryos before implanting them in the mother’s uterus, called preimplantation genetic diagnosis, or PGD, can lower the risk of having children with XLH.

For IVF, clinicians combine eggs from the mother and sperm from the father in a laboratory to make multiple embryos. Clinicians can take small samples of cells from the embryos to perform PGD. Depending on the results of the tests, you can decide whether you want to move forward with the pregnancy. If you decide to go ahead, your doctor will implant one or more of the embryos into the uterus.

Other reproductive options

If you and/or your partner have XLH and don’t want to test your future children genetically, you can choose to use eggs/and or sperm from a donor for the IVF procedure. In this case, the child will not be genetically related to one or both of you.

If you are a woman with XLH and there are health concerns for you carrying the child, you can choose to use IVF and have a surrogate carry the pregnancy to term.

Last updated: Sept. 18, 2020

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XLH News Today is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.