What is Noonan Syndrome?

An inherited condition that affects development in several areas of the body, Noonan syndrome was formerly called Turner-like syndrome. It is caused by defects in genes that provide over-activity to proteins involved with growth and development. Is it a dominant condition, only one parent needs to have the trait for it to be passed down.

Symptoms

Some of the signs of this condition include wide-set eyes or down-slanting eyes, delayed puberty, hearing loss, short stature, small penis, sagging eyelids, low-set ears, abnormally-shaped ears, undescended testicles, webbed or short neck, and an unusual chest shape. 25 percent of those with the condition will have mild mental retardation.

Diagnosis

The doctor does a physical exam, checking for the above symptoms and any signs of congenital heart disease. Other tests may include genetic testing, hearing tests, blood clotting factor test, platelet count, chest x-ray, echocardiogram, and an EKG.

Treatment

There are no treatments specific to the relief of Noonan syndrome. There will just be lifestyle adjustments and management of symptoms. Some may see some value in growth hormones. Some of the complications that can occur from having the condition include social difficulties, low self-esteem, heart structure problems, male infertility, failure to thrive, and a buildup of fluid in the tissues.

This condition may be seen as early as infanthood. Those with a family history of the condition can seek genetic counseling prior to conceiving and have genetic testing done after conception to check for Noonan syndrome.

Source: A.D.A.M.