biostudies-arrayexpressMetabolomicsUnknownTranscriptomicsGenomicsProteomicsArnault TAUZIEDEmethylation profiling by arrayYersinia enterocoliticaYersinia enterocoliticahttps://www.ebi.ac.uk/biostudies/studies/E-MTAB-17457Two studies originating from the same team have previously suggested the existence of tectal glioma (TG) as a distinct pediatric low grade circumscribed astrocytic tumor type enriched in KRAS alterations or KRAS and BRAF concomitant alterations, and characterized by a distinct methylation profile. Although the majority of these tumors display a pilocytic astrocytoma (PA) morphology, the imprecise terminology of “glioma” was preferred by these authors. The inclusion of the entity “tectal glioma with KRAS mutation” in a future WHO classification is still under discussion. In this context, we performed a comprehensive analysis of 35 glial tumors located in the tectum including clinical, radiological, histopathological, and molecular data. The majority of tumors encountered were pilocytic astrbiostudies-arrayexpressSample Collection - Genomic DNA was extracted from fresh-frozen or formalin-fixed and paraffin-embedded (FFPE) tissue samples.Scaning - Genomic DNA was extracted from fresh-frozen or formalin-fixed and paraffin-embedded (FFPE) tissue samples.Nucleic Acid Extraction - Genomic DNA was extracted from fresh-frozen or formalin-fixed and paraffin-embedded (FFPE) tissue samples.Labeling - Genomic DNA was extracted from fresh-frozen or formalin-fixed and paraffin-embedded (FFPE) tissue samples.Hybridization - Genomic DNA was extracted from fresh-frozen or formalin-fixed and paraffin-embedded (FFPE) tissue samples.MIAME ScoreRaw DataOrganizationAssays and DataProcessed DataMAGE-TAB FilesArray DesignsArnault TAUZIEDEData Transformation - Each sample was individually normalized by performing a background correction (shifting of the 5% percentile of negative control probe intensities to 0) and a dye-bias correction (scaling of the mean of normalization control probe intensities to 10,000) for both color channels. Subsequently, a correction for the type of material tissue (FFPE/frozen) and array type (450k/EPIC) was performed by fitting univariable, linear models to the log2-transformed intensity values (removeBatchEffect function, limma package version 3.30.11). The methylated and unmethylated signals were corrected individually. Beta-values were calculated from the retransformed intensities using an offset of 100 (as recommended by Illumina). All samples were checked for duplicates by pairwise correlatfalseTECTAL GLIOMA VERSUS PILOCYTIC ASTROCYTOMA: REVISITING TUMOR CLASSIFICATION IN LIGHT OF MOLECULAR HETEROGENEITYTwo studies originating from the same team have previously suggested the existence of tectal glioma (TG) as a distinct pediatric low grade circumscribed astrocytic tumor type enriched in KRAS alterations or KRAS and BRAF concomitant alterations, and characterized by a distinct methylation profile. Although the majority of these tumors display a pilocytic astrocytoma (PA) morphology, the imprecise terminology of “glioma” was preferred by these authors. The inclusion of the entity “tectal glioma with KRAS mutation” in a future WHO classification is still under discussion. In this context, we performed a comprehensive analysis of 35 glial tumors located in the tectum including clinical, radiological, histopathological, and molecular data. The majority of tumors encountered were pilocytic astr2026-08-19T00:00:00Z2026-08-19T01:00:44.594Z2026-08-04T11:38:45.055ZE-MTAB-17457EFO_0002944EFO_0003814EFO_0003813EFO_0002759EFO_0005518EFO_0003816EFO_0003815