What is (are) Costello syndrome ?
Costello syndrome is a rare condition that affects many different parts of the body. Signs and symptoms generally include developmental delay, intellectual disability, distinctive facial features, loose folds of extra skin (especially on the hands and feet), and unusually flexible joints. Affected people may also have heart abnormalities such as tachycardia, structural heart defects, and hypertrophic cardiomyopathy. Beginning in early childhood, people with Costello syndrome are at an increased risk of developing certain cancerous and noncancerous tumors. Costello syndrome is caused by changes (mutations) in the HRAS gene. It is considered an autosomal dominant condition; however, almost all reported cases are the result of de novo gene mutations and occur in people with no family history of the condition. Treatment is based on the signs and symptoms present in each person.