TOP2A
Chr 17DNA topoisomerase II alpha
Also known as: TOP2, TOP2alpha, TOPIIA, TP2A
This gene encodes a DNA topoisomerase, an enzyme that controls and alters the topologic states of DNA during transcription. This nuclear enzyme is involved in processes such as chromosome condensation, chromatid separation, and the relief of torsional stress that occurs during DNA transcription and replication. It catalyzes the transient breaking and rejoining of two strands of duplex DNA which allows the strands to pass through one another, thus altering the topology of DNA. Two forms of this enzyme exist as likely products of a gene duplication event. The gene encoding this form, alpha, is localized to chromosome 17 and the beta gene is localized to chromosome 3. The gene encoding this enzyme functions as the target for several anticancer agents and a variety of mutations in this gene have been associated with the development of drug resistance. Reduced activity of this enzyme may also play a role in ataxia-telangiectasia. [provided by RefSeq, Jul 2010]
Primary Disease Associations & Inheritance
Some data sources returned errors (1)
ensembl: Error: Ensembl fetch failed: 500 for https://rest.ensembl.org/lookup/symbol/homo_sapiens/TOP2A?content-type=application/json&expand=1
Population Genetics & Constraint
gnomAD v4 — loss-of-function & missense intolerance
Highly LoF-intolerant (top ~10% of genes)
Highly missense-constrained (top ~0.1%)
ClinVar Variant Classifications
141 submitted variants in ClinVar
Classification Summary
Curated Variants Distribution
Classified variants from ClinVar · 5 ACMG categories
| Classification | LoF | Missense + Inframe | Non-coding | Synonymous | Total |
|---|---|---|---|---|---|
Pathogenic | 0 | 0 | 8 | 0 | 8 |
Likely Pathogenic | 0 | 0 | 0 | 0 | 0 |
VUS | 0 | 102 | 1 | 0 | 103 |
Likely Benign | 0 | 12 | 1 | 7 | 20 |
Benign | 0 | 2 | 1 | 6 | 9 |
Conflicting | — | 1 | |||
| Total | 0 | 116 | 11 | 13 | 141 |
LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly
View in ClinVar →Protein Context — Lollipop Plot
TOP2A · protein map & ClinVar variants
Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.
OMIM — Genotype-Phenotype Relationships
1 OMIM entry
DNA topoisomerase II, resistance to inhibition of, by amsacrine
Molecular basis of disorder known
External Resources
Links to major genomics databases and tools
Clinical Trials
Active and recruiting trials from ClinicalTrials.gov
Preliminary Experimental Study on Key Technologies for Early Screening of Gastric Cancer
RECRUITINGProspective Cohort Study of Liver Cancer Patients Treated With Proton Beam Therapy
ENROLLING BY INVITATIONExternal Resources
Links to major genomics databases and tools