Gliomas represent the most common primary intraparenchymal tumors of the central 
nervous system in adults and children and are a genetic and phenotypic 
heterogeneous group. Large multi-institutional studies and The Cancer Genome 
Atlas have provided firm insights into the basic genetic drivers in gliomas. The 
main molecular biomarkers routinely applied to evaluate diffuse gliomas include 
MGMT promoter methylation, EGFR alterations (eg, EGFRvIII), IDH1 or IDH2 
mutations, and 1p19q co-deletion. Many of these markers have become standard of 
care for molecular testing and prerequisites for clinical trial enrollment. 
Other recent biomarkers include TERT promoter and ATRX mutations, alterations 
that identify specific molecular subgroups of diffuse gliomas with biological 
and clinical relevance. It has also become apparent that distinctive patterns of 
molecular genetic evolution develop in the context of current therapeutic 
regimens. Important insights have also been uncovered in the field of pediatric 
glioma, including the identification of recurrent mutation, fusion, and/or 
duplication events of the BRAF, FGFR1, MYB, and MYBL1 genes in pediatric 
low-grade gliomas, mutations affecting histone components (H3F3A p.K27M or 
p.G34) in pediatric high-grade gliomas, and aggressive subsets developing in 
midline central nervous system structures. Here, we summarize current concepts 
in molecular testing for glial tumors, including recent findings by large-scale 
discovery efforts and technologic advances that are affecting routine diagnostic 
work.