If My Child Has Sanfilippo, Will the Next Child Inherit It Too?

Emily Malcolm, PhD avatar

by Emily Malcolm, PhD |

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Sanfilippo inheritance

If you have a child with Sanfilippo syndrome, you may be wondering whether having another child may put that child at risk of inheriting the disease as well.

How is Sanfilippo syndrome inherited?

Sanfilippo syndrome is caused by mutations in genes that provide instructions for cells to make proteins that help break down particular types of sugar molecules called glycosaminoglycans (GAGs). As a result, these GAGs build up in cells and tissues, interfering with their function and leading to the symptoms of Sanfilippo syndrome.

A child has to inherit two copies of a disease-causing mutation (one from each parent) to develop Sanfilippo syndrome. This is called a recessive inheritance pattern.

What is the risk of future children inheriting Sanfilippo?

If you have a child with Sanfilippo syndrome, both you and your partner are likely carriers of the disease. Carriers have a single copy of a disease-causing mutation, and also a healthy copy of the gene that can help compensate for the mutated one. Carriers generally don’t have any symptoms of the disease. Therefore, they may not know they are carriers until they have an affected child.

Genetic testing can determine if you and your partner are carriers. If you are planning to have more children, discuss your family’s medical history with a genetic counselor, who can explain the results of the genetic tests to you. They can also help you figure out your reproductive options.

If you and your partner are carriers, each child that you have together has a one in four chance of inheriting two copies of a disease-causing mutation and developing Sanfilippo syndrome. Your children also have a one in two chance of being carriers like you. Finally, they have a one in two chance of inheriting a healthy copy of the gene from both you and your partner, and will not have the disease or be a carrier.

What are my reproductive options?

You can minimize the risk of your children inheriting Sanfilippo syndrome with reproductive options such as in vitro fertilization and pre-implantation genetic diagnosis. Your baby can also undergo genetic testing before birth.

Discuss your options with your doctor and genetic counselor, who can help you determine the one best suited for your family.


Last updated: June 30, 2020


Sanfilippo Syndrome News 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.