H3F3A mutations are seen in ∼30% of pediatric glioblastoma (GBMs) and involve either the lysine residue at position 27 (K27M) or glycine at position 34 (G34R/V).
Recent studies on high-grade pediatric GBM have identified two recurrent mutations (K27M and G34R/V) in genes encoding histone H3 (H3F3A for H3.3 and HIST1H3B for H3.1).
Exon sequencing has identified a mutation in K27M of the histone H3.3 gene (H3F3A K27M and G34R/V) in about 20% of pediatric glioblastomas, but it remains to be seen whether these mutations can be considered specific for pediatric diffuse high-grade astrocytomas or also occur in other pediatric brain tumors.
Because H3F3A K27M mutations occur exclusively in pediatric diffuse high-grade astrocytomas, analysis of codon 27 mutational status could be useful in the differential diagnosis of these neoplasms.
Patients with tumours harbouring a K27M mutation in H3.3 (H3F3A) did not respond clinically to radiotherapy as well, relapsed significantly earlier and exhibited more metastatic recurrences than those in H3.1 (HIST1H3B/C).
As compared to H3 K27M-wildtype tumo</span>rs, there were no differences in age at diagnosis, sex, tumor grade, contrast enhancement on MRI, extent of resection, or treatment received.
We demonstrate in this first series of midline GGs that the H3 K27M mutation can occur in association with the BRAF V600E mutation in grade I glioneuronal tumors.
Evaluation of histone 3 lysine 27 trimethylation (H3K27me3) and enhancer of Zest 2 (EZH2) in pediatric glial and glioneuronal tumors shows decreased H3K27me3 in H3F3A K27M mutant glioblastomas.
We identified an increased number of iCNA in older children compared to infants, and increased iCNA in H3F3A K27M mutant tumours compared to G34R/V and wild-type.
Histologically, the tumor was considered to be glioblastoma; however, a part of the tumor exhibiting low proliferative activity appeared to be consistent with long-standing H3 K27M-mutant tumors in the literature.Another case was a 69-year-old male.
Histologically, the tumor was considered to be glioblastoma; however, a part of the tumor exhibiting low proliferative activity appeared to be consistent with long-standing H3 K27M-mutant tumors in the literature.Another case was a 69-year-old male.