Professional
Technical
IVT
H3K27M mutation
Pronunciation: H-three-K-twenty-seven-M
Histone mutation defining diffuse midline glioma, associated with poor prognosis and specific anatomical locations.
Full Definition
H3K27M mutation is a specific alteration in histone H3 genes (H3F3A or HIST1H3B) that results in substitution of lysine 27 with methionine. This mutation defines diffuse midline glioma, H3K27M-mutant, a distinct entity in the WHO classification that typically occurs in midline structures such as the brainstem, thalamus, and spinal cord. These tumors carry a grave prognosis regardless of histological grade and represent a paradigm shift toward molecular-based brain tumor classification.
Usage
Usage note: Use exact notation H3K27M; do not abbreviate or alter the alphanumeric sequence.
In Context
- "Immunohistochemistry revealed H3K27M mutation, confirming the diagnosis of diffuse midline glioma." — Pediatric neuropathology report
- "The brainstem lesion tested positive for H3K27M mutation, indicating an aggressive diffuse midline glioma." — Molecular diagnostic report
Also known as
histone H3K27M alteration
Contrasted with
H3K27 wild-type
Don't confuse with
H3K36M mutation
H3G34R mutation