Noonan Syndrome

What is Noonan Syndrome?

Noonan Syndrome is a disorder caused by a genetic mutation that causes various parts of the patient’s body to develop abnormally. The condition occurs when a parent passes on an affected gene to their child that produces constantly active proteins, leading to a disruption in the process of normal cell division and growth.

Science currently knows of eight genes in which a mutation can cause the disorder. In some cases, there is no family history and the mutation is spontaneous.

What are the Symptoms of Noonan Syndrome?

One of the main indications of Noonan syndrome is the abnormal development of the person’s face, which varies at different ages. Newborn babies generally have low-set ears, slanting or wide-set eyes, and a short neck, among other features.

Infants can develop thickened eyelids as their eyes become more prominent, while a young child’s face may seem devoid of expression. A teenager’s facial features tend to sharpen, and an adult’s skin could appear transparent and become wrinkled.

Other common symptoms and complications that result from Noonan syndrome include:

  • Congenital heart disease
  • Thickened heart muscle
  • Heart valve disorders
  • Heart structural defects
  • Growth issues in childhood
  • Short stature in adults
  • Musculoskeletal issues
  • Eye abnormalities
  • Learning disabilities
  • Lymphatic disorders
  • Bleeding
  • Easy bruising
  • Urinary tract complications
  • Skin conditions
  • Kidney problems
  • Delayed puberty
  • Genital abnormalities

How is Noonan Syndrome Treated?

There is no way to cure or prevent Noonan syndrome, so treatment is focused on relieving the resulting complications. Therapies will vary depending on severity and the nature of symptoms.

Heart problems can be controlled through medications and, if necessary, surgery. Children with a slow growth rate may be given growth hormone therapy. Learning disabilities can be improved through various speech and physical therapies, while patients who bleed or bruise easily should avoid aspirin. Glasses are often sufficient for vision issues, although conditions like cataracts might require surgery.

Last Reviewed:
October 07, 2016
Last Updated:
August 10, 2017