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Noonan Syndrome

Short stature caused by Noonan syndrome, a genetic condition, can sometimes be treated with growth hormone therapy. Norditropin® is used to treat children who are short (in stature) and who have Noonan syndrome.

Noonan syndrome is a rare disorder that affects both boys and girls. While many body systems may be affected by Noonan syndrome, one of the most common signs in patients is that they are shorter than other children their age. Children with Noonan syndrome are usually born with normal birth weight and length. But when they reach early childhood, their growth starts to slow down. Up to 83% of patients with Noonan syndrome have short stature. For reasons that are unclear, they simply do not grow normally.

Along with short stature, some of the other common physical traits of Noonan syndrome may be:

  • Heart defects
  • Increased bruising or bleeding
  • Uncommon facial features
  • Low-set ears with forward-facing lobes
  • Delay in puberty
  • Poor eyesight
  • Chest and skeletal deformities
  • Webbed neck
  • Low hairline at the back of the neck

Everyone is different: Some children may have many of these features, while others have just a few. Because children with Noonan syndrome usually have more than one of these traits, most likely they will need to see other medical specialists, like a heart specialist (cardiologist) or an eye specialist (ophthalmologist).

A genetic cause.

The cause of Noonan syndrome is not completely understood, but it appears to be a mutation, or abnormal change, in one of several genes. The way Noonan syndrome affects the patient depends on which gene is changed.

At present there is no simple test that can diagnose a child with Noonan syndrome. At first, the diagnosis is made by physical features like short stature, heart problems, and unusual facial features. Afterward a genetic test may be done. It is helpful if you can tell doctors about any family members who have been diagnosed with Noonan syndrome.

More resources.

Patients and their families can find support, community, and education through various patient organizations. Visit the Noonan Syndrome Foundation or see all Patient Advocacy Groups.