Lekárska genetika a diagnostika 1/2026
Diagnosis of CNS tumors based on DNA methylation profiling
The diagnosis of CNS tumors increasingly relies on molecular approaches, particularly DNA methylation profiling. DNA methylation is a stable epigenetic biomarker enabling accurate classification even in histologically ambiguous cases. The Illumina EPIC/EPIC2 methylation arrays are widely used in clinical practice and provide robust results even from FFPE samples. Interpretation is based on the Heidelberg brain tumor classifier, whose current version v12.8 includes 184 methylation classes. Importantly, methylation profiling also allows inference of copy number alterations, such as CDKN2A deletions or 1p/19q codeletion, which support prognostic and therapeutic decisions. This method is especially valuable in pediatric neuro-oncology, where many entities lack alternative diagnostic markers. Despite limitations such as low tumor cellularity or “no match” outcomes, DNA methylation classification is a key component of integrated WHO CNS5 diagnostics.
Keywords: DNA methylation, CNS tumor, methylation classifier, chromosomal alteration
