Mayo Clinic Health Manager
Get free personalized health guidance for you and your family.
Get StartedTests and diagnosis
By Mayo Clinic staffA diagnosis of Noonan syndrome is usually made after a doctor observes some of the key signs and symptoms of the disease, but this can be difficult because some of the features associated with this disorder are subtle and can be hard to identify. Many times, Noonan syndrome isn't diagnosed until adulthood, after a person has a child who is more obviously affected by the condition. Molecular genetic testing can be used to make a definitive diagnosis.
If there's evidence of heart problems, your doctor will likely recommend an electrocardiogram (ECG) and an echocardiogram to assess the type and severity of the condition. The ECG involves placing electrodes on your chest. An ECG looks at the electrical impulses that travel through your heart to assess problems. An echocardiogram uses sound waves to create a moving image of your heart working so that your doctor can see where there may be problems. These tests are usually done by a doctor who specializes in heart conditions (cardiologist).
- Noonan syndrome. Genetics Home Reference. http://ghr.nlm.nih.gov/condition=noonansyndrome. Accessed Oct. 22, 2008.
- Learning about Noonan syndrome. National Human Genome Research Institute. http://www.genome.gov/25521674. Accessed Oct. 22, 2008.
- Allanson JE. Noonan syndrome. American Journal of Medical Genetics. 2007;145C: 274-279.
- Allanson JE. Noonan syndrome. GeneReviews. http://www.ncbi.nlm.nih.gov/bookshelf/br.fcgi?book=gene&part=noonan. Accessed Oct. 22, 2008.
- Lin AE. Adults with genetic syndromes and cardiovascular abnormalities: Clinical history and management. Genetics in Medicine. 2008;10(7):469-494.
- DeLuca A. NF1 gene mutations represent the major molecular event underlying neurofibromatosis-Noonan syndrome. The American Journal of Human Genetics. 2005;77(6):1092-1011.
- Tullu MS. Neurofibromatosis-Noonan syndrome or LEOPARD syndrome? A clinical dilemma. Journal of Postgraduate Medicine. 2000;46(2):98-100.
- Hoecker JL (expert opinion). Mayo Clinic, Rochester, Minn. Oct. 23, 2008.