Omics · study · 2026
An exceptionally rare case of a diffuse midline glioma with concomitant H3.1 K27M and G34R mutations in the HIST1H3C (H3C3) gene [RNA-seq]
Listed in NCBI GEO
Histone mutations (H3 K27M, H3 G34R/V) are molecular features defining subtypes of paediatric-type diffuse high-grade gliomas (HGG) (diffuse midline glioma (DMG), H3 K27-altered, diffuse hemispheric glioma (DHG), H3 G34-mutant).
Description
The WHO classification recognises in exceptional cases, these mutations co-occur. We report one such case of a 2-year-old female presenting with neurological symptoms; MRI imaging identified a brainstem lesion which was biopsied.
Histology showed diffusely infiltrating pleomorphic astrocytes, multinucleated cells, and conspicuous mitotic activity; the diagnosis was DMG, H3 K27-altered (immunohistochemistry: H3K27me3 loss, H3K27M positivity). DNA methylation profiling (Illumina EPIC BeadArrays, brain tumour classifier (MNP v12.5 R package)) classified the tumour as ‘DMG, H3 K27-altered’ (calibrated score=0.99). Further molecular studies (whole exome, whole genome sequencing) revealed concurrent H3.1 K27M and G34R mutations (clonal, in the same reads) of H3C3, FGF11 and PIK3CA somatic variants, and a pathogenic germline NBN variant.
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The RNAseq profile clustered with H3K27M-mutant tumours. A patient-derived cell culture was established enabling unbiased in vitro drug screening; no selective sensitivities were identified. Chromatin immunoprecipitation assays with sequencing (ChIP-seq; H3K27ac, H3K27me3, H3K36me3, RNApol2 marks) showed features in keeping with DMG H3 K27M-mutant tumours (H3K27ac loci including OLIG2, IRX1/2, PKDCC).
The patient was treated with adjuvant radiotherapy, but progressed and passed away 13 months post-diagnosis. This case is an exceptionally rare, complex variant of histone-mutant paediatric HGG, illustrating that the H3.1 K27M mutation demonstrates a dominance over the molecular and clinical profiles compared to G34R, and highlights the importance of broad molecular profiling to identify such examples for further study.
Links
Get the data
- GEO FTP directory ftp.ncbi.nlm.nih.gov/geo/series/GSE283nnn/GSE283685 ↗
download · from NCBI GEO
Where it is published
- GEO accession page ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE283685 ↗
landing page · from NCBI GEO
Documentation and papers
- PRJNA1195040 ncbi.nlm.nih.gov/bioproject/PRJNA1195040 ↗
project · from NCBI GEO
Topics
- Stated by source
- Expression profiling by high throughput sequencing · Homo sapiens
- From keywords
- Life Sciences
- Inferred from text
- Cancer 65% · DNA methylation profiling 75% · Genome sequencing 75% · Imaging 75% · Magnetic resonance imaging 65% · RNA sequencing 65% · Sequencing 75%
Provenance · 1 source records, 14 field assertions
| Source | Key | Last seen | Raw |
|---|---|---|---|
| NCBI GEO | GSE283685 | 13 d ago | JSON v1 |
| Field | Assertion | Extractor | Evidence |
|---|---|---|---|
| access_level | source · NCBI GEO | connector:ncbi_geo@1.0.0 | |
| concepts[disease].local:disease:cancer | enrichment · NCBI GEO | keyword-concept-rules@1.0.0 | title+description (65%) |
| concepts[field].local:field:life-sciences | mapping · NCBI GEO | connector:ncbi_geo@1.0.0 | |
| concepts[method].geo_series_type:expression-profiling-by-high-throughput-sequencing | source · NCBI GEO | connector:ncbi_geo@1.0.0 | /gdstype |
| concepts[method].local:method:dna-methylation-profiling | enrichment · NCBI GEO | keyword-concept-rules@1.0.0 | title+description (75%) |
| concepts[modality].local:modality:genome-sequencing | enrichment · NCBI GEO | keyword-concept-rules@1.0.0 | title+description (75%) |
| concepts[modality].local:modality:imaging | enrichment · NCBI GEO | keyword-concept-rules@1.0.0 | title+description (75%) |
| concepts[modality].local:modality:mri | enrichment · NCBI GEO | keyword-concept-rules@1.0.0 | title+description (65%) |
| concepts[modality].local:modality:rna-seq | enrichment · NCBI GEO | keyword-concept-rules@1.0.0 | title+description (65%) |
| concepts[modality].local:modality:sequencing | enrichment · NCBI GEO | keyword-concept-rules@1.0.0 | title+description (75%) |
| concepts[organism].NCBITaxon:9606 | source · NCBI GEO | connector:ncbi_geo@1.0.0 | /taxon |
| description | source · NCBI GEO | connector:ncbi_geo@1.0.0 | /summary |
| publication_date | source · NCBI GEO | connector:ncbi_geo@1.0.0 | |
| title | source · NCBI GEO | connector:ncbi_geo@1.0.0 | /title |