MSD Manual

Please confirm that you are not located inside the Russian Federation

honeypot link

Noonan Syndrome

(Noonan's Syndrome)

By

Nina N. Powell-Hamilton

, MD, Sidney Kimmel Medical College at Thomas Jefferson University

Reviewed/Revised Nov 2023
VIEW PROFESSIONAL VERSION

Noonan syndrome is a genetic defect that causes a number of physical abnormalities, including short stature, heart defects, and an abnormal appearance.

Noonan syndrome is caused by mutations in certain genes that can be inherited from a parent who has an affected gene. It also can occur spontaneously in a child whose parents do not have an affected gene. One of several different genes may be involved.

Noonan syndrome is relatively common, occurring in about 1 in 1,000 to 2,500 people. Both boys and girls can be affected.

Symptoms of Noonan Syndrome

Diagnosis of Noonan Syndrome

  • Genetic testing

To confirm the diagnosis of Noonan syndrome, genetic tests are done.

Treatment of Noonan Syndrome

  • Surgical repair of heart defects

  • Growth hormone therapy

  • For boys, sometimes testosterone hormone replacement therapy

There is no cure for Noonan syndrome. However, some specific symptoms and problems caused by the syndrome can be treated. Doctors monitor and repair heart defects as needed.

Growth may be stimulated by treatment with growth hormone. After satisfactory growth, testosterone hormone replacement therapy may help boys whose testes are underdeveloped.

Children suspected of having Noonan syndrome should be evaluated for heart, vision, and hearing problems.

NOTE: This is the Consumer Version. DOCTORS: VIEW PROFESSIONAL VERSION
VIEW PROFESSIONAL VERSION
quiz link

Test your knowledge

Take a Quiz! 
iOS ANDROID
iOS ANDROID
iOS ANDROID
TOP