Astrocytoma, IDH-mutant

Central Nervous System Tumours (WHO Classification, 5th ed.)

Primary Author(s)*

Meenakshi Mehrotra, PhD, Mount Sinai Health System, New York

WHO Classification of Disease

Structure	Disease
Book	Central Nervous System Tumours (5th ed.)
Category	Gliomas, glioneuronal tumours, and neuronal tumours
Family	Gliomas, glioneuronal tumours, and neuronal tumours
Type	Adult-type diffuse gliomas
Subtype(s)	Astrocytoma, IDH-mutant

Related Terminology

Acceptable	N/A
Not Recommended	Diffuse astrocytoma, IDH-mutant; anaplastic astrocytoma, IDH-mutant; glioblastoma, IDH-mutant; low-grade astrocytoma; lower-grade astrocytoma; high-grade astrocytoma; infiltrating astrocytoma; diffuse glioma

Gene Rearrangements

Driver Gene	Fusion(s) and Common Partner Genes	Molecular Pathogenesis	Typical Chromosomal Alteration(s)	Prevalence -Common >20%, Recurrent 5-20% or Rare <5% (Disease)	Diagnostic, Prognostic, and Therapeutic Significance - D, P, T	Established Clinical Significance Per Guidelines - Yes or No (Source)	Clinical Relevance Details/Other Notes
MET	PTPRZ1::MET	N/A	N/A	Rare (~1%)	P	No	MET fusions and splicing variants convergently define a subgroup of glioma sensitive to MET inhibitors
NTRK2	GOLGA1::NTRK2	N/A	N/A	Rare (observed in single case report)	P, T	No	Single case report
NTRK2	CDK5RAP2::NTRK2	N/A	N/A	Rare (observed in single case report)	P, T	No	Single case report

Individual Region Genomic Gain/Loss/LOH

Put your text here and fill in the table (Instructions: Includes aberrations not involving gene rearrangements. Details on clinical significance such as prognosis and other important information can be provided in the notes section. Can refer to CGC workgroup tables as linked on the homepage if applicable. Please include references throughout the table. Do not delete the table.)

Chr #	Gain, Loss, Amp, LOH	Minimal Region Cytoband and/or Genomic Coordinates [Genome Build; Size]	Relevant Gene(s)	Diagnostic, Prognostic, and Therapeutic Significance - D, P, T	Established Clinical Significance Per Guidelines - Yes or No (Source)	Clinical Relevance Details/Other Notes
9	loss	chr9:21,967,752-21,995,324	CDKN2A	P	Yes  (WHO CNS5)	Poorer prognosis
9	loss	chr9:22,002,903-22,009,313	CDKN2B	P	Yes  (WHO CNS5)	Poorer prognosis
12	amp	chr12:57,747,727-57,756,013	CDK4	P,T	No	Poorer prognosis
13	loss	chr13:48,303,744-48,599,436	RB1	P	No
4	amp	chr4:54,229,280-54,298,245	PDGFRA	P	No	Poorer prognosis
2	amp	chr2:15,940,550-15,947,007	MYCN	P	No	PMID: 29687258; PMID: 37185778; poorer prognosis
7	amp	chr7:116,672,196-116,798,377	MET		No	PMID: 31667475
10	loss	chr10:87863113-87971930	PTEN	P	No	PMID: 37185778

Characteristic Chromosomal or Other Global Mutational Patterns

Put your text here and fill in the table (Instructions: Included in this category are alterations such as hyperdiploid; gain of odd number chromosomes including typically chromosome 1, 3, 5, 7, 11, and 17; co-deletion of 1p and 19q; complex karyotypes without characteristic genetic findings; chromothripsis; microsatellite instability; homologous recombination deficiency; mutational signature pattern; etc. Details on clinical significance such as prognosis and other important information can be provided in the notes section. Please include references throughout the table. Do not delete the table.)

Chromosomal Pattern	Molecular Pathogenesis	Prevalence - Common >20%, Recurrent 5-20% or Rare <5% (Disease)	Diagnostic, Prognostic, and Therapeutic Significance - D, P, T	Established Clinical Significance Per Guidelines - Yes or No (Source)	Clinical Relevance Details/Other Notes
EXAMPLE: Co-deletion of 1p and 18q	EXAMPLE: See chromosomal rearrangements table as this pattern is due to an unbalanced derivative translocation associated with oligodendroglioma (add reference).	EXAMPLE: Common (Oligodendroglioma)	EXAMPLE: D, P
EXAMPLE: Microsatellite instability - hypermutated		EXAMPLE: Common (Endometrial carcinoma)	EXAMPLE: P, T

Gene Mutations (SNV/INDEL)

Put your text here and fill in the table (Instructions: This table is not meant to be an exhaustive list; please include only genes/alterations that are recurrent or common as well either disease defining and/or clinically significant. If a gene has multiple mechanisms depending on the type or site of the alteration, add multiple entries in the table. For clinical significance, denote associations with FDA-approved therapy (not an extensive list of applicable drugs) and NCCN or other national guidelines if applicable; Can also refer to CGC workgroup tables as linked on the homepage if applicable as well as any high impact papers or reviews of gene mutations in this entity. Details on clinical significance such as prognosis and other important information such as concomitant and mutually exclusive mutations can be provided in the notes section. Please include references throughout the table. Do not delete the table.)

Gene	Genetic Alteration	Tumor Suppressor Gene, Oncogene, Other	Prevalence - Common >20%, Recurrent 5-20% or Rare <5% (Disease)	Diagnostic, Prognostic, and Therapeutic Significance - D, P, T	Established Clinical Significance Per Guidelines - Yes or No (Source)	Clinical Relevance Details/Other Notes
EXAMPLE:EGFR	EXAMPLE: Exon 18-21 activating mutations	EXAMPLE: Oncogene	EXAMPLE: Common (lung cancer)	EXAMPLE: T	EXAMPLE: Yes (NCCN)	EXAMPLE: Exons 18, 19, and 21 mutations are targetable for therapy. Exon 20 T790M variants cause resistance to first generation TKI therapy and are targetable by second and third generation TKIs (add references).
EXAMPLE: TP53; Variable LOF mutations	EXAMPLE: Variable LOF mutations	EXAMPLE: Tumor Supressor Gene	EXAMPLE: Common (breast cancer)	EXAMPLE: P		EXAMPLE: >90% are somatic; rare germline alterations associated with Li-Fraumeni syndrome (add reference). Denotes a poor prognosis in breast cancer.
EXAMPLE: BRAF; Activating mutations	EXAMPLE: Activating mutations	EXAMPLE: Oncogene	EXAMPLE: Common (melanoma)	EXAMPLE: T

Note: A more extensive list of mutations can be found in cBioportal, COSMIC, and/or other databases. When applicable, gene-specific pages within the CCGA site directly link to pertinent external content.

Epigenomic Alterations

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Genes and Main Pathways Involved

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Gene; Genetic Alteration	Pathway	Pathophysiologic Outcome
EXAMPLE: BRAF and MAP2K1; Activating mutations	EXAMPLE: MAPK signaling	EXAMPLE: Increased cell growth and proliferation
EXAMPLE: CDKN2A; Inactivating mutations	EXAMPLE: Cell cycle regulation	EXAMPLE: Unregulated cell division
EXAMPLE: KMT2C and ARID1A; Inactivating mutations	EXAMPLE: Histone modification, chromatin remodeling	EXAMPLE: Abnormal gene expression program

Genetic Diagnostic Testing Methods

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Familial Forms

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Additional Information

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Links

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References

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Notes

*Primary authors will typically be those that initially create and complete the content of a page.  If a subsequent user modifies the content and feels the effort put forth is of high enough significance to warrant listing in the authorship section, please contact the Associate Editor or other CCGA representative.  When pages have a major update, the new author will be acknowledged at the beginning of the page, and those who contributed previously will be acknowledged below as a prior author.

Prior Author(s): *Citation of this Page: “Astrocytoma, IDH-mutant”. Compendium of Cancer Genome Aberrations (CCGA), Cancer Genomics Consortium (CGC), updated 09/4/2025, https://ccga.io/index.php/CNS5:Astrocytoma, IDH-mutant.