GTPase HRas

GTPase HRas is a small GTPase protein (189 amino acids) encoded by the HRAS gene that functions as a molecular switch in Ras protein signal transduction pathways. The protein binds and hydrolyzes guanosine nucleotides (GDP/GTP), enabling activation of downstream signaling cascades (UniProt: P01112).

HRAS mutations are associated with several syndromic and malignant conditions. Costello syndrome, a rare developmental disorder characterized by prenatal overgrowth, postnatal growth deficiency, intellectual disability, distinctive facial features, cardiovascular abnormalities, and tumor predisposition, results from HRAS dysregulation. The gene is also implicated in non-medullary thyroid cancer, bladder cancer, and Schimmelpenning-Feuerstein-Mims syndrome, a condition featuring sebaceous nevi with associated central nervous system and skeletal abnormalities (UniProt: P01112).

HRAS carries SFARI syndromic (S) classification, indicating a curated association with autism in the context of genetic syndromes (SFARI Cat S). This reflects the intellectual disability and neurodevelopmental features observed in HRAS-related Costello syndrome cases.