Noonan Syndrome

National Organization for Rare Disorders, Inc.

Skip to the navigation

Important
It is possible that the main title of the report Noonan Syndrome is not the name you expected.

Disorder Subdivisions

  • None

General Discussion

Noonan syndrome is a genetic disorder that is typically evident at birth (congenital). The disorder is characterized by a wide spectrum of symptoms and physical features that vary greatly in range and severity. In many affected individuals, associated abnormalities include a distinctive facial appearance; a broad or webbed neck; a low posterior hairline; a typical chest deformity and short stature. Characteristic features of the head and facial (craniofacial) area may include widely set eyes (ocular hypertelorism); skin folds that may cover the eyes' inner corners (epicanthal folds); drooping of the upper eyelids (ptosis); a small jaw (micrognathia); a depressed nasal root; a short nose with broad base; and low-set, posteriorly rotated ears (pinnae). Distinctive skeletal malformations are also typically present, such as abnormalities of the breastbone (sternum), curvature of the spine (kyphosis and/or scoliosis), and outward deviation of the elbows (cubitus valgus). Many infants with Noonan syndrome also have heart (cardiac) defects, such as obstruction of proper blood flow from the lower right chamber of the heart to the lungs (pulmonary valvular stenosis) and thickening of the ventricular heart muscle (hypertrophic cardiomyopathy). Additional abnormalities may include malformations of certain blood and lymph vessels, blood clotting and platelet deficiencies, learning difficulties or mild intellectual disability, failure of the testes to descend into the scrotum (cryptorchidism) by the first year of life in affected males, and/or other symptoms and findings.

Noonan syndrome is an autosomal dominant genetic disorder caused by abnormalities (mutations) in more than eight genes. The five most commonly involved genes are: PTPN11 (50%), SOS1 (10-13%), RAF1(5%), RIT1 (5%), and KRAS (less than 5%). Fewer individuals have a mutation in NRAS, BRAF, MEK2, RRAS, RASA2, A2ML1, SOS2, and LZTR1. Noonan-like disorders are found in association with mutations in SHOC2 and CBL.

Supporting Organizations

American Heart Association

7272 Greenville Avenue
Dallas, TX 75231
Tel: (214)784-7212
Fax: (214)784-1307
Tel: (800)242-8721
Email: Review.personal.info@heart.org
Website: http://www.heart.org

Children's Cardiomyopathy Foundation

PO Box 547
Tenafly, NJ 7670
USA
Tel: (866)808-2873
Fax: (201)227-7016
Email: info@childrenscardiomyopathy.org
Website: http://www.childrenscardiomyopathy.org

Genetic and Rare Diseases (GARD) Information Center

PO Box 8126
Gaithersburg, MD 20898-8126
Tel: (301)251-4925
Fax: (301)251-4911
Tel: (888)205-2311
Website: http://rarediseases.info.nih.gov/GARD/

Human Growth Foundation

997 Glen Cove Avenue
Suite 5
Glen Head, NY 11545
Tel: (516)671-4041
Fax: (516)671-4055
Tel: (800)451-6434
Email: hgf1@hgfound.org
Website: http://www.hgfound.org/

MAGIC Foundation

6645 W. North Avenue
Oak Park, IL 60302
Tel: (708)383-0808
Fax: (708)383-0899
Tel: (800)362-4423
Email: contactus@magicfoundation.org
Website: http://www.magicfoundation.org

March of Dimes

1275 Mamaroneck Avenue
White Plains, NY 10605
Tel: (914)997-4488
Fax: (914)997-4763
Email: AskUs@marchofdimes.org or preguntas@nacersano.org
Website: http://www.marchofdimes.org and nacersano.org

NIH/National Heart, Lung and Blood Institute

P.O. Box 30105
Bethesda, MD 20892-0105
Tel: (301)592-8573
Fax: (301)251-1223
Email: nhlbiinfo@rover.nhlbi.nih.gov
Website: http://www.nhlbi.nih.gov/

RASopathies Network USA

244 Taos Road
Altadena, CA 91001-3953
Tel: (626)676-7694
Email: info@rasopathiesnet.org
Website: http://www.rasopathiesnet.org

Restricted Growth Association

PO Box 5137
Yeovil, BA20 9FF
United Kingdom
Tel: 3001111970
Fax: 3001112454
Email: office@restrictedgrowth.co.uk
Website: http://www.restrictedgrowth.co.uk

The Arc

1825 K Street NW, Suite 1200
Washington, DC 20006
Tel: (202)534-3700
Fax: (202)534-3731
Tel: (800)433-5255
Email: info@thearc.org
Website: http://www.thearc.org

For a Complete Report

This is an abstract of a report from the National Organization for Rare Disorders (NORD). For a full-text version of this report, go to www.rarediseases.org and click on Rare Disease Database under "Rare Disease Information".

The information provided in this report is not intended for diagnostic purposes. It is provided for informational purposes only.

It is possible that the title of this topic is not the name you selected. Please check the Synonyms listing to find the alternate name(s) and Disorder Subdivision(s) covered by this report.

This disease entry is based upon medical information available through the date at the end of the topic. Since NORD's resources are limited, it is not possible to keep every entry in the Rare Disease Database completely current and accurate. Please check with the agencies listed in the Resources section for the most current information about this disorder.

Last Updated:  8/18/2016
Copyright  2016 National Organization for Rare Disorders, Inc.