Noonan syndrome is a disease that can be passed down through families (inherited). It causes abnormal development in many parts of the body. Noonan syndrome used to be called Turner-like syndrome.
Causes, incidence, and risk factors
Noonan syndrome is linked to defects in several genes. Problems with the genes cause certain proteins involved in growth and development to become overactive.
Noonan syndrome is an autosomal dominant condition. This means only one parent has to pass down the faulty gene for the baby to have the syndrome. However, some cases may not be inherited.
Unusual chest shape (usually a sunken chest called pectus excavatum)
Webbed and short-appearing neck
Signs and tests
The health care provider will perform a physical exam. This may show signs of congenital heart disease (especially pulmonary stenosis, occasionally ASD).
There is no specific treatment. Your doctor will suggest treatment to relieve or manage symptoms. Growth hormone has been used successfully to treat short stature in some persons with Noonan syndrome.
Buildup of fluid in tissues of body (lymphedema, cystic hygroma)
Failure to thrive in infants
Low self-esteem
Male infertility in those with both testes undescended
Problems with the structure of the heart
Short stature
Social difficulties related to physical symptoms
Calling your health care provider
This condition may be detected on early infant exams. Evaluation by an experienced geneticist is often needed to diagnose Noonan syndrome.
Prevention
Couples with a family history of Noonan syndrome may want to consider genetic counseling before having children.
References
Rapaport R. Hypofunction of the ovaries. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 18th ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 587.
Review Date:
4/16/2012
Reviewed By:
A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, and David R. Eltz. Previously reviewed by Chad Haldeman-Englert, MD, Wake Forest University School of Medicine, Department of Pediatrics, Section on Medical Genetics, Winston-Salem, NC. Review provided by VeriMed Healthcare Network (8/4/2011).
