Costello Syndrome

**Definition:** Rare congenital disorder with multiple anomalies including: characteristic dysmorphic craniofacial features, musculoskeletal abnormalities, neurocognitive delay, and high prevalence of cancer. Germline mutations in H-Ras protein can cause Costello syndrome. Costello syndrome shows early phenotypic overlap with other disorders that involve MAP KINASE SIGNALING SYSTEM (e.g., NOONAN SYNDROME and cardiofaciocutaneous syndrome).

**Tree numbers:** - C05.660.207.219 - C16.131.077.256 - C16.320.188

**Synonyms:** - Faciocutaneoskeletal Syndrome - FCS Syndrome