Noonan Syndrome (Pediatric)

What is Noonan syndrome?

Noonan syndrome is a genetic condition that presents at birth or prenatally, with characteristic facial and body features, and is frequently associated with short stature, heart defects, bleeding disorders, and skeletal malformations. Noonan syndrome affects boys and girls.

What causes Noonan syndrome?

Noonan syndrome is caused by a gene mutation that may affect one of several genes. About half of the cases are caused by a PTPN11 gene mutation and 10-15 percent are caused by a SOS1 gene mutation. Other cases include the RAF1 and RIT1 gene mutations. These genes are all associated with the RAS/MAPK cell signaling pathway, which is involved in crucial cell activities. About 15-20 percent of patients with Noonan syndrome do not have an identifiable gene mutation.

What are the symptoms of Noonan syndrome?

This condition is associated with short stature, heart defects, bleeding disorders, delayed puberty, and skeletal malformations. Children affected by Noonan syndrome generally have characteristic facial and body features such as low-set ears, a small lower jaw, and a short and webbed neck.

How is Noonan syndrome diagnosed?

Noonan syndrome is diagnosed when a patient presents with several of the features associated with this disorder. Genetic testing is performed to determine if the patient has one of the gene mutations associated with Noonan syndrome.

What is the treatment for Noonan syndrome?

Some children with Noonan syndrome will benefit from treatment with growth hormone to help with their growth.

Children with Noonan syndrome generally have normal intelligence although some do require special education. They may be at an increased risk of developing leukemia and other cancers.

Care for children with Noonan syndrome is multidisciplinary and they should be evaluated and followed by a clinical geneticist, a cardiologist, an orthopedist, and an endocrinologist.