Our Noonan-Spectrum Disorders Clinic in the Department of Genetics and Metabolism provides comprehensive care for children and adults with a suspected or confirmed diagnosis of Noonan syndrome, Cardiofaciocutaneous syndrome, Costello syndrome, and Noonan syndrome with Multiple Lentigines (previously called LEOPARD syndrome). Our team of experts can schedule timely clinical genetics evaluations for these patients.
What to Expect from Your Visit
Each visit involves obtaining medical and family histories, clinical exam, genetic counseling, and recommendations for genetic testing and additional specialist visits. Appropriate referrals will be provided to patients as needed including endocrinology, cardiology, gastroenterology, and neurosurgery. We also coordinate opportunities for involvement in clinical research.
The clinic meets at Children’s National main hospital location and at the Montgomery County Outpatient Center.
For more information, please visit our website Genetics and Metabolism. Please feel free to contact us for more information or to refer a patient.
Noonan syndrome is characterized by short stature, congenital heart defects, variable developmental delays, and distinctive features that may include low set ears, wide-spaced eyes, and ptosis. Other features include broad neck, low set nipples, chest abnormalities, coagulation defects, and ocular abnormalities. Congenital heart disease is seen in the majority of individuals, the most common type being pulmonary valve stenosis. Intellectual disability is seen in about one-third of patients and is typically mild. Many adults are often undiagnosed.
Cardiofaciocutaneous syndrome is associated with cardiac anomalies including pulmonary valve stenosis, septal defects, and hypertrophic cardiomyopathy. Distinctive craniofacial appearance is seen, including high forehead, macrocephaly, bitemporal narrowing, hypertelorism, down slanting palpebral fissures, epicanthal folds, ptosis, and low set ears. Features are typically more coarse than those seen in Noonan syndrome. Cutaneous abnormalities and hair differences including fine/thick, woolly hair and abnormal eyebrows/eyelashes are cardinal features. Neurocognitive delays are present in nearly all individuals.
Costello syndrome is characterized by failure to thrive in infancy, feeding difficulties, short stature, developmental delay/intellectual disability, and coarse features which include full lips and nasal tip, large mouth, and curly or sparse fine hair. Joint laxity, soft skin, and papillomata are common features. Cardiac defects including hypertrophic cardiomyopathy, pulmonary valve stenosis, and arrhythmia are typical. Costello syndrome is associated with a 15 percent lifetime risk for rhabdomyosarcoma and neuroblastoma in young children, and transitional cell carcinoma of the bladder in adolescents.
Noonan syndrome with Multiple Lentigines
Noonan syndrome with multiple lentigines is characterized by lentigines, ECG conduction abnormalities, ocular hypertelorism, pulmonic stenosis, abnormal genitalia, growth retardation, and sensorineural hearing loss. More than 80 percent have heart defects, including hypertrophic cardiomyopathy and pulmonary valve stenosis. Mild intellectual disability is noted in approximately 30 percent of patients. Skeletal abnormalities have also been reported.
There are multiple genes associated with these conditions. All of the Noonan-Spectrum disorders are inherited in an autosomal dominant manner.