Noonan syndrome is a disease that can be passed down through families (inherited). It causes many parts of the body to develop abnormally.
Noonan syndrome is linked to defects in several genes. In general, certain proteins involved in growth and development become overactive as a result of these gene changes.
Noonan syndrome is an autosomal dominant condition. This means only one parent has to pass down the nonworking gene for the child to have the syndrome. However, some cases may not be inherited.
Tests depend on the symptoms, but may include:
Genetic testing can help diagnose this syndrome.
There is no specific treatment. Your provider will suggest treatment to relieve or manage symptoms. Growth hormone has been used successfully to treat short height in some persons with Noonan syndrome.
Complications may include:
This condition may be found during early infant exams. A geneticist is often needed to diagnose Noonan syndrome.
Couples with a family history of Noonan syndrome may want to consider genetic counseling before having children.
Ali O, Donohoue PA. Noonan syndrome. In: Kliegman RM, Stanton BF, St Geme JW, Schor NF, eds. Nelson Textbook of Pediatrics. 20th ed. Philadelphia, PA: Elsevier; 2016:chap 583.
Allanson JE, Roberts AE. Noonan syndrome. GeneReviews. Seattle, WA: University of Washington; 2011:11.
Last reviewed on: 1/25/2016
Reviewed by: Chad Haldeman-Englert, MD, FACMG, Fullerton Genetics Center, Asheville, NC. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.