THIRD EDITION
Factsheet
Condition:
Noonan syndrome
Inheritance:
Autosomal dominant
Genetic Etiology:
Mutation in KRAS or PTPN11 genes.
Frequency:
1/1,000–1/2,500
Clinical features:
Short stature, characteristic facial appearance with tall forehead and downslanting palpebral fissures, heart defects (especially pulmonic stenosis and hypertrophic cardiomyopathy), lymphatic anomalies, bleeding diathesis, renal anomalies, developmental delay.
Management:
Surgery for correctable congenital anomalies; supportive care.
Genetic counseling:
May occur sporadically or be inherited from a parent; genetic testing is available.