Noonan Syndrome - Genes

Do you know which gene is responsible for your Noonan syndrome?

Share your story with others:

MedicineNet appreciates your comment. Your comment may be displayed on the site and will always be published anonymously.Patient Comments FAQs

Enter your Comment

Tell us a bit about your background to make your comments more useful to other MedicineNet users. (Optional)

Screen Name: *

Gender of Patient: Male Female

Age Range of Patient:

I am a: Patient Caregiver


* Screen Name will appear next to the published comment. Please do not include your full name or email address.

By submitting your comment, and other materials (collectively referred to as a "Submission") to MedicineNet, you grant MedicineNet permission to use, copy, transmit, publish, display, edit and modify your Submission in connection with its Web site. MedicineNet will not pay you for your Submission. You represent that you have all rights necessary for MedicineNet to use your Submission as set forth above.

Please keep these guidelines in mind when writing your comment:

  • Please make sure you address the question asked.
  • Due to the overwhelming number of comments received, not all comments will be published.
  • When selecting comments to publish, our staff will choose those that are educational and complement the topic. Please try to stay on topic.
  • Your comment may be edited. We would typically edit comments to make them clearer and more readable. We will remove personal information such as last names, email and web addresses, and other potentially harmful information.
  • We will not notify you if your comment has been published. We suggest that you check back on the topic article regularly.
  • We do not provide medical or healthcare advice, treatment, or diagnosis.

Thank you for participating!


I have read and agree to abide by the MedicineNet Terms and Conditions and the MedicineNet Privacy Policy (required).

To prevent our systems from spam, please complete the following prior to submitting your comment.

Please select the white circle:

What genes are related to Noonan syndrome?

Mutations in the PTPN11, SOS1, RAF1, KRAS, NRAS and BRAF genes cause Noonan syndrome.

Most cases of Noonan syndrome result from mutations in one of three genes, PTPN11, SOS1, or RAF1. PTPN11 gene mutations account for approximately 50 percent of all cases of Noonan syndrome. SOS1 gene mutations account for 10 to 15 percent and RAF1 gene mutations account for 5 to 10 percent of Noonan syndrome cases. About 2 percent of people with Noonan syndrome have mutations in the KRAS gene and usually have a more severe or atypical form of the disorder. It is not known how many cases are caused by mutations in the BRAF or NRAS genes, but it is likely a very small proportion. The cause of Noonan syndrome in the remaining 20 percent of people with this disorder is unknown.

The PTPN11, SOS1, RAF1, KRAS, NRAS and BRAF genes all provide instructions for making proteins that are important in signaling pathways needed for the proper formation of several types of tissue during development. These proteins also play roles in cell division, cell movement, and cell differentiation (the process by which cells mature to carry out specific functions). Mutations in any of the genes listed above cause the resulting protein to be continuously active, rather than switching on and off in response to cell signals. This constant activation disrupts the regulation of systems that control cell growth and division, leading to the characteristic features of Noonan syndrome.

Return to Noonan Syndrome

STAY INFORMED

Get the latest health and medical information delivered direct to your inbox!