CDKN2A deletion
Pronunciation: C-D-K-N-two-A
Loss of the CDKN2A tumor suppressor gene, used as a molecular marker for diagnosing diffuse astrocytoma, IDH-mutant, grade 4.
Full Definition
Homozygous deletion of the cyclin-dependent kinase inhibitor 2A gene, which encodes the p16 protein and is located on chromosome 9p21. In the context of neuropathology, CDKN2A deletion serves as a molecular marker that, when present in IDH-mutant astrocytomas without traditional grade 4 histological features, assigns a grade 4 designation according to current WHO criteria. This molecular alteration indicates more aggressive biological behavior and worse prognosis, even in histologically lower-grade appearing tumors.
Usage
Usage note: Always specify homozygous vs. heterozygous deletion status when reporting results.
In Context
- "CDKN2A deletion was detected by FISH analysis, upgrading the tumor to grade 4 despite benign histology." — Molecular pathology report
- "The presence of CDKN2A deletion in this IDH-mutant astrocytoma warrants aggressive treatment protocols." — Multidisciplinary team meeting