Molecular profiling is key for early, accurate diagnosis1
A molecularly confirmed H3 K27M–mutant diffuse midline glioma (DMG) diagnosis can inform prognosis and treatment plans2,3
Unlock guideline-concordant diagnosis and classification of DMG with molecular profiling1
Imaging alone cannot confirm mutational status, but biopsy with subsequent molecular testing can reveal specific mutations, like H3 K27M, to help inform and optimize disease management.1,4,5
- NGS
- Next generation sequencing (NGS) can detect a broad range of genomic alterations to identify specific mutations and potential therapeutic targets4,6
- IHC
- Immunohistochemistry (IHC) is a widely accessible and sensitive method for identifying H3 K27M–mutant protein expression and assessing H3 K27me3 status using specific antibodies4,7,8
- Methylation profiling
- DNA methylation-based analysis can offer objective, more precise tumor classification but should not be used as a first-line test before NGS or IHC in H3 K27M–mutant DMG2,3
If tissue samples are limited, the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®) for Pediatric Central Nervous System Cancers recommends prioritizing NGS, limited IHC panel, hematoxylin and eosin histology, and methylation profiling.2
The 3 common genetic alterations associated with H3 K27M–mutant DMG are1,9-12,*:
H3F3A
(H3.3K27M)
HIST1H3B
(H3.1K27M)
HIST1H3C
(H3.1K27M)
A fourth, rare mutation associated with H3 K27M–mutant DMG is HIST2H3C.10
*H3F3A may be reported as H3-3A. HIST1H3B may be reported as H3C2. HIST1H3C may be reported as H3C3. The terms p.K28M, H3-3A:c.83A>T p.Lys28Met, and K27M refer to the same mutation (H3 K27M). This is due to differences in protein numbering systems and whether or not they count the initiating methionine in a protein sequence. H3 K27M is the oncology standard terminology for this mutation per the WHO classification, while H3 K28M may be reported in sequencing results.4,13-17
The latest WHO classification of central nervous system tumors focuses on molecular alterations, as identifying these mutations can improve diagnostic accuracy and guide treatment plans.1
Testing Panel | Test type | Sample type | Lab website |
|---|---|---|---|
Mayo Clinic Labs Histone Genes Mutation Analysis | NGS | Tumor tissue | Visit Mayo Clinic Labs Histone Genes Mutation Analysis (opens in a new tab) |
Mayo Clinic Labs Neuro-Oncology Expanded Gene Panel | NGS | Tumor tissue | Visit Mayo Clinic Labs Neuro-Oncology Expanded Gene Panel (opens in a new tab) |
Quest Diagnostics Solid Tumor Expanded Panel | NGS | Tumor tissue | Visit Quest Diagnostics Solid Tumor Expanded Panel (opens in a new tab) |
University of Washington OncoPlex Cancer Gene Panel | NGS | Tumor tissue | Visit University of Washington OncoPlex Cancer Gene Panel (opens in a new tab) |
University of Pittsburgh Medical Center GlioSeq® - NGS Panel for Brain Tumors | NGS | Tumor tissue | |
UT MD Anderson Cancer Center Genetic Testing Services | NGS and single-cell analysis | Tumor tissue, cerebrospinal fluid, and blood | Visit UT MD Anderson Cancer Center Genetic Testing Services (opens in a new tab) |
CARIS Life Sciences Testing Portfolio | NGS | Tumor tissue and blood | Visit CARIS Life Sciences Testing Portfolio (opens in a new tab) |
Tempus Life Sciences Sequencing Portfolio | NGS, RNA sequencing, multi-gene panels | Tumor tissue and blood | Visit Tempus Life Sciences Sequencing Portfolio (opens in a new tab) |
NeoGenomics Immunohistochemistry for H3K27me3 | Immunohistochemistry | Tumor tissue | Visit NeoGenomics Immunohistochemistry for H3K27me3 (opens in a new tab) |
Foundation Medicine Genomic Testing Portfolio | NGS, RNA sequencing, immunohistochemistry | Tumor tissue and blood | Visit Foundation Medicine Genomic Testing Portfolio (opens in a new tab) |
This is not an exhaustive list. Other academic centers may provide testing services.
Uncover the H3 K27M mutation to inform
the course of DMG treatment.2,3
DNA, deoxyribonucleic acid; H3, histone 3; K, lysine; M, methionine; me3, trimethylation; RNA, ribonucleic acid; WHO, World Health Organization.
References: 1. Horbinski C, Solomon DA, Lukas RV, et al. Molecular testing for the World Health Organization classification of central nervous system tumors: a review. JAMA Oncol. 2025;11(3):317-328. 2. Referenced with permission from the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®) for Pediatric Central Nervous System Cancers V.1.2026. © National Comprehensive Cancer Network, Inc. 2025. All rights reserved. Accessed July 24, 2026. To view the most recent and complete version of the guideline, go online to NCCN.org. NCCN makes no warranties of any kind whatsoever regarding their content, use or application and disclaims any responsibility for their application or use in any way. 3. Referenced with permission from the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®) for Central Nervous System Cancers V.3.2026. © National Comprehensive Cancer Network, Inc. 2026. All rights reserved. Accessed August 28, 2026. To view the most recent and complete version of the guideline, go online to NCCN.org. NCCN makes no warranties of any kind whatsoever regarding their content, use or application and disclaims any responsibility for their application or use in any way. 4. Vallero SG, Bertero L, Morana G, et al. Pediatric diffuse midline glioma H3K27-altered: a complex clinical and biological landscape behind a neatly defined tumor type. Front Oncol. 2023;12:1082062. 5. Gajjar A, Mahajan A, Bale T, et al. Pediatric central nervous system cancers, version 2.2025. J Natl Compr Canc Netw. 2025;23(3):113-130. 6. Kim T, Lee A, Ahn S, Park JS, Jeun SS, Lee YS. Comprehensive molecular genetic analysis in glioma patients by next generation sequencing. Brain Tumor Res Treat. 2024;12(1):23-39. 7. Bechet D, Gielen GG, Korshunov A, et al. Specific detection of methionine 27 mutation in histone 3 variants (H3K27M) in fixed tissue from high-grade astrocytomas. Acta Neuropathol. 2014;128(5):733-741. 8. Penkova A, Kuziakova O, Gulaia V, et al. Comprehensive clinical assays for molecular diagnostics of gliomas: the current state and future prospects. Front Mol Biosci. 2023;10:1216102. 9. Schwartzentruber J, Korshunov A, Liu XY, et al. Driver mutations in histone H3.3 and chromatin remodelling genes in paediatric glioblastoma. Nature. 2012;482(7384):226-231. 10. Castel D, Philippe C, Calmon R, et al. Histone H3F3A and HIST1H3B K27M mutations define two subgroups of diffuse intrinsic pontine gliomas with different prognosis and phenotypes. Acta Neuropathol. 2015;130(6):815-827. 11. Wu G, Broniscer A, McEachron TA, et al. Somatic histone H3 alterations in pediatric diffuse intrinsic pontine gliomas and non-brainstem glioblastomas. Nat Genet. 2012;44(3):251-253. 12. Buczkowicz P, Hoeman C, Rakopoulos P, et al. Genomic analysis of diffuse intrinsic pontine gliomas identifies three molecular subgroups and recurrent activating ACVR1 mutations. Nat Genet. 2014;46(5):451-456. 13. Louis DN, Perry A, Wesseling P, et al. The 2021 WHO Classification of Tumors of the Central Nervous System: a summary. Neuro Oncol. 2021;23(8):1231-1251. 14. Broggi G, Salzano S, Failla M, et al. Clinico-pathological features of diffuse midline glioma, H3 K27–altered in adults: a comprehensive review of the literature with an additional single-institution case series. Diagnostics (Basel). 2024;14(23):2617. 15. Symbol report for H3-3A. HUGO Gene Nomenclature Committee. Accessed September 28, 2026. https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:4764 16. Symbol report for H3C2. HUGO Gene Nomenclature Committee. Accessed September 28, 2026. https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:4776 17. Symbol report for H3C3. HUGO Gene Nomenclature Committee. Accessed September 28, 2026. https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:4768