Diagnosis

A diagnosis of Noonan syndrome is usually made after a doctor observes some key signs, but this can be difficult because some features are subtle and hard to identify. Sometimes, Noonan syndrome isn't diagnosed until adulthood, only after a person has a child who is more obviously affected by the condition. Molecular genetic testing can help confirm a diagnosis.

If there's evidence of heart problems, a doctor who specializes in heart conditions (cardiologist) can assess the type and severity.