Please note: This information was current at the time of publication but now may be out of date. This handout provides a general overview and may not apply to everyone. 

brand logo

Am Fam Physician. 2014;89(1):online

See related article on Noonan syndrome.

What is Noonan syndrome?

Noonan syndrome is a genetic disorder. This is something you're born with, not something you can catch. It causes some parts of your body to develop abnormally. About one in every 2,000 babies is born with Noonan syndrome.

People with Noonan syndrome can have many different physical traits:

  • Your eyes may be spaced far apart, or your ears may be lower than normal.

  • You may have a deep groove in the space between your nose and mouth.

  • Your neck may look thick and webbed.

  • Your chest may look like it's caved in or it may stick out.

  • You may be shorter than other people.

  • You may have problems with your heart.

  • You may bleed easily.

  • If you're a male, you may have problems having children.

How is it diagnosed?

Usually, a doctor can diagnose a person based on how he or she looks. Doctors can also test a person's genes. These tests aren't perfect, however. Noonan syndrome might be caused by changes in other genes that we aren't yet aware of.

Can it be treated?

There is no specific cure for Noonan syndrome. If you have the disease, your family doctor may refer you to other doctors who specialize in treating specific body parts or systems. These specialists will test your heart, blood, eyes, ears, and nervous system to make sure everything is okay.

If you or someone in your family has Noonan syndrome, there is a chance that you can pass the genes that cause the disease on to your children.

Where can I get more information?

Your doctor


Genetics Home Reference

Continue Reading

More in AFP

Copyright © 2014 by the American Academy of Family Physicians.

This content is owned by the AAFP. A person viewing it online may make one printout of the material and may use that printout only for his or her personal, non-commercial reference. This material may not otherwise be downloaded, copied, printed, stored, transmitted or reproduced in any medium, whether now known or later invented, except as authorized in writing by the AAFP.  See permissions for copyright questions and/or permission requests.