Which oncogene product is a constitutively active GTPase caused by a point mutation that prevents intrinsic GTP hydrolysis, perpetuating downstream MAPK signaling?

• A BCR-ABL1
• B MYC
• C EGFR
• D RAS (KRAS/NRAS/HRAS) ✓

Explanation

Point mutations in RAS (most commonly KRAS codon 12 or 13) impair the intrinsic GTPase activity that normally terminates RAS signaling; RAS remains locked in the GTP-bound active state, continuously activating RAF-MEK-ERK (MAPK) and PI3K-AKT pathways. BCR-ABL1 is a constitutively active tyrosine kinase fusion; MYC is a transcription factor; EGFR is a receptor tyrosine kinase.

Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.