Costello syndrome is a genetic disorder that affects many parts of the body. This condition is characterized by delayed development and mental retardation, distinctive facial features, loose folds of extra skin (especially on the hands and feet), and unusually flexible joints. Heart abnormalities are common, including a very fast heartbeat (tachycardia), structural heart defects, and overgrowth of the heart muscle (hypertrophic cardiomyopathy). Infants with Costello syndrome may be large at birth, but have difficulty feeding and grow more slowly than other children. Later in life, people with this condition have relatively short stature and many lack growth hormone.
* Short stature * Delayed bone age * Loose, lax, stretchy skin - around the neck, palms, soles and fingers * Curly hair * Papillomata (small fleshy growths) around the mouth and nose * A characteristic facial appearance (wide nostrils, depressed nasal bridge, low-set ears with large earlobes) * Broad mouth and thick lips * Pigmented skin * Drooping of the upper eyelid (ptosis) * Squint (strabismus)
It is now known that mutations in the HRAS gene causes Costello syndrome. This gene is involved in the manufacture of a protein that helps control cell growth and division. In Costello syndrome mutations of this gene cause cells to grow and divide constantly rather than in response to specific signals to do so. This constant abnormal cell division and overgrowth results in cancerous and non-cancerous tumour growth and is thought to be responsible for the other characteristic signs of Costello syndrome.
The pattern of overgrowth in the womb, poor growth after birth, and short height is typical of individuals with Costello syndrome. Other clinical features, especially the loose, wrinkled skin and graying, curly hair give them an aged appearance that is quite distinct. The skin papules found in the nose, mouth, and on the anus add to the picture. Taking these features together, the diagnosis can be made.
The severe problems with feeding and growth that characterize Costello syndrome can be life-threatening. Most of these infants need to be fed with a feeding tube in order to survive. Complications of heart disease are another cause for concern, even early in life. For most individuals, however, the heart problems are not severe, and usually can be successfully treated without heart surgery.
There's no cure for Costello syndrome but treatments are in development. However, supportive care - from help with feeding in early childhood to special education - and treatment for complications such as heart problems can help affected children reach their potential.