Costello syndrome is caused by a mutation (abnormality) of the HRAS gene. Only about 350 reports of Costello syndrome have been published in worldwide medical literature, so it is not clear how often the syndrome actually occurs or who is more likely to be affected by it.
Symptoms
Most children with Costello syndrome have difficulty eating, gaining weight, and growing.
Typical symptoms of Costello syndrome are:
Difficulty gaining weight and growing after birth, which leads to short statureExcessive loose skin on the neck, palms of the hands, fingers, and soles of the feet (cutis laxa)Noncancerous growths (papillomata) around the mouth and nostrilsCharacteristic facial appearance such as a large head, low-set ears with large, thick lobes, thick lips, and/or wide nostrilsMental retardationThickened, dry skin on the hands and feet or arms and legs (hyperkeratosis)Abnormally flexible joints of the fingers.
Some individuals may have restricted movement at the elbows or tightening of the tendon at the back of the ankle. Individuals with Costello syndrome may have heart defects or cardiomyopathy. There is a high incidence of tumor growth, both cancerous and noncancerous, associated with the syndrome as well.
Diagnosis
Similarly presenting conditions include Noonan Syndrome or cardiofaciocutaneous syndrome, which are also rare. The diagnosis of Costello syndrome is made based on clinical findings and the identification of a pathogenic variant of the HRAS gene via molecular genetic testing.
Costello Syndrome is due to an autosomal dominant mutation in HRAS and should not be diagnosed unless this mutation is present.
This mutation is believed to occur sporadically, which means that it is not inherited from the child’s parents.
Treatment
There is no specific treatment for Costello syndrome, so medical care focuses on the effects and symptoms. It is recommended that all individuals with Costello syndrome have a cardiology evaluation to look for heart defects and heart disease.
Physical therapy and occupational therapy can help an individual reach their developmental potential, physically and cognitively. Long-term monitoring for tumor growth, spine or orthopedic problems, and heart or blood pressure changes is also important.
