Q (haiku): What are the top 5 most frequently mutated genes in the Osteosarcoma study from TARGET? ▶ read_guide { "uri": "cbioportal://mutation-frequency-guide" } ▶ clickhouse_list_tables {} ◀ result # Mutation Frequency Analysis Guide ## IMPORTANT: Reporting Mutation Frequencies - **ALWAYS report frequencies as percentages**, not raw counts: `frequency = (altered_samples / total_profiled_samples) × 100` - For quick frequency lookups, **prefer the TCGA Pan-Cancer Atlas study first**, then offer to expand to other studies - When reporting across multiple studies, show **ranges** (e.g., "TP53 is mutated in 30–60% of samples") rather than a single average - **NEVER** sum mutation events across studies to compute an aggregate frequency — this can exceed 100% due to double-counting - Warn users that samples may overlap across cohorts (e.g., MSK studies may share patients) - **Choose and state the counting unit**: use patient-level frequencies for prevalence/rate questions unless the user explicitly asks for samples; use sample-level frequencies when the user asks about samples. - **For "across cancer types" questions**, jump to the [Cross-Cancer-Type Mutation Frequency](#cross-cancer-type-mutation-frequency) section below — there is one correct recipe and several common wrong ones. ## Counting Unit: Samples vs Patients Before answering any mutation count or frequency question, decide whether the unit is samples or patients and state that choice in the answer. | User wording | Counting unit | |--------------|---------------| | "prevalence", "rate", "fraction of patients", "patients with", "how common is" | Patient-level: `COUNT(DISTINCT patient_unique_id)` | | "samples", "specimens", "biopsies", sample-level cohort composition | Sample-level: `COUNT(DISTINCT sample_unique_id)` | | Ambiguous | Ask, or default to patient-level for prevalence/rate language and say so | ### Cross-study sample-count caveat When an answer touches more than one study and reports a sample count, prepend a one-line caveat: > Sample IDs are unique within cBioPortal study prefixes, not guaranteed biological-sample identifiers across studies; overlapping cohorts can count the same patient/sample more than once. Prefer one of these safer approaches: - Use a shipped `cancer_study_query_preferences` cohort such as `pan_cancer_tcga` or `all_studies_non_redundant`. - Restrict to one named study. - Aggregate by `patient_unique_id` when the biological question is patient prevalence. ## STOP rule: a frequency above 100% means your query is wrong If your query returns a frequency over 100%, **do not try to debug or explain the data inconsistency to the user**. The cause is always one of these query bugs: - Summing mutation events instead of `COUNT(DISTINCT sample_unique_id)` for the numerator - Using a study-wide sample count as the denominator instead of the gene-specific profiled count - Cross-study aggregation where the same biological sample appears under multiple `sample_unique_id` values (e.g., MSK-IMPACT and MSK-CHORD share patients) - **Joining the profiled CTE through `gene_panel` / `gene_panel_list` without a WES branch.** `gene_panel_id = 'WES'` is *not* a row in … (35166 more chars) ◀ result {"tables":[{"name":"allele_specific_copy_number"},{"name":"alteration_driver_annotation"},{"name":"cancer_study"},{"name":"cancer_study_query_preferences"},{"name":"cancer_study_tags"},{"name":"cbioportal_sequence_state"},{"name":"clinical_attribute_counts"},{"name":"clinical_attribute_meta"},{"name":"clinical_data_derived"},{"name":"clinical_event"},{"name":"clinical_event_data"},{"name":"clinical_event_data_derived"},{"name":"clinical_event_derived"},{"name":"clinical_patient"},{"name":"clinical_sample"},{"name":"cna_event"},{"name":"cna_panel_gene_coverage"},{"name":"cna_wes_coverage"},{"name":"co_altered_genes_in_study"},{"name":"copy_number_seg"},{"name":"copy_number_seg_file"},{"name":"gene"},{"name":"gene_alias"},{"name":"gene_alteration_frequency_by_cancer_type"},{"name":"gene_cna_distribution_in_study"},{"name":"gene_mutation_frequency_by_cancer_type"},{"name":"gene_mutation_frequency_in_studies"},{"name":"gene_mutation_frequency_in_study"},{"name":"gene_mutation_variants_in_study"},{"name":"gene_pair_coexpression"},{"name":"gene_panel"},{"name":"gene_panel_list"},{"name":"gene_panel_to_gene_derived"},{"name":"generic_assay_data_derived"},{"name":"generic_assay_meta_derived"},{"name":"generic_assay_profile_entity_derived"},{"name":"generic_entity_properties"},{"name":"geneset"},{"name":"geneset_gene"},{"name":"geneset_hierarchy_leaf"},{"name":"geneset_hierarchy_node"},{"name":"genetic_alteration"},{"name":"genetic_alteration_derived"},{"name":"genetic_entity"},{"name":"genetic_profile"},{"name":"genetic_profile_link"},{"name":"genetic_profile_samples"},{"name":"genomic_event_derived"},{"name":"gistic"},{"name":"gistic_to_gene"},{"name":"info"},{"name":"mut_sig"},{"name":"mutation"},{"name":"mutation_count_by_keyword"},{"name":"mutation_derived"},{"name":"mutation_event"},{"name":"mutation_panel_gene_coverage"},{"name":"mutation_wes_coverage"},{"name":"patient"},{"name":"reference_genome"},{"name":"reference_genome_gene"},{"name":"resource_definition"},{"name":"resource_patient"},{"name":"resource_sample"},{"name":"resource_study"},{"name":"sample"},{"name":"sample_cna_event"},{"name":"sample_derived"},{"name":"sample_list"},{"name":"sample_list_list"},{"name":"sample_profile"},{"name":"sample_to_gene_panel_derived"},{"name":"structural_variant"},{"name":"sv_panel_gene_coverage"},{"name":"sv_wes_coverage"},{"name":"top_cna_genes_in_study"},{"name":"top_mutated_genes_in_cohort"},{"name":"top_mutated_genes_in_study"},{"name":"top_sv_genes_in_study"},{"name":"treatment_counts_in_study"},{"name":"treatment_regimens_in_study"},{"name":"type_of_cancer"}]} ▶ clickhouse_run_select_query { "query": " SELECT DISTINCT cancer_study_identifier, name FROM cancer_study WHERE lower(name) LIKE '%target%' AND lower(name) LIKE '%osteosarcoma%' ", "max_rows": 10 } ◀ result {"rows":[{"cancer_study_identifier":"os_target_gdc","name":"Osteosarcoma (TARGET GDC, 2025)"}]} ▶ clickhouse_run_select_query { "query": " SELECT hugo_gene_symbol, altered_samples, profiled_samples, frequency_pct, total_mutation_events FROM top_mutated_genes_in_study(study = 'os_target_gdc', top_n = 5) ORDER BY altered_samples DESC ", "max_rows": 10 } ◀ result {"rows":[{"hugo_gene_symbol":"TP53","altered_samples":32,"profiled_samples":143,"frequency_pct":22.4,"total_mutation_events":33},{"hugo_gene_symbol":"MUC16","altered_samples":16,"profiled_samples":143,"frequency_pct":11.2,"total_mutation_events":17},{"hugo_gene_symbol":"TTN","altered_samples":16,"profiled_samples":143,"frequency_pct":11.2,"total_mutation_events":18},{"hugo_gene_symbol":"ATRX","altered_samples":11,"profiled_samples":143,"frequency_pct":7.7,"total_mutation_events":11},{"hugo_gene_symbol":"DNAH9","altered_samples":10,"profiled_samples":143,"frequency_pct":7,"total_mutation_events":10}]} ▶ resolve_and_route { "studyIds": [ "os_target_gdc" ] } ◀ result {"success":true,"message":"Found 1 study. Use the metadata to call the appropriate navigation tool(s).","data":{"totalCount":1,"studiesWithMetadata":[{"studyId":"os_target_gdc","name":"Osteosarcoma (TARGET GDC, 2025)","sampleCount":159,"studyViewUrl":"https://www.cbioportal.org/study?id=os_target_gdc","metadata":{"clinicalAttributeIds":["AGE","CANCER_TYPE","CANCER_TYPE_DETAILED","DAYS_TO_BIRTH","DAYS_TO_DEATH","DISEASE_TYPE","ETHNICITY","MUTATION_COUNT","ONCOTREE_CODE","OS_MONTHS","OS_STATUS","PRIMARY_DIAGNOSIS","PRIMARY_SITE_PATIENT","PROJECT_ID","RACE","SAMPLE_COUNT","SEX","SPECIMEN_TYPE","TMB_NONSYNONYMOUS","VITAL_STATUS"],"molecularProfileIds":["os_target_gdc_cna","os_target_gdc_mrna_seq_fpkm","os_target_gdc_mrna_seq_fpkm_Zscores","os_target_gdc_mrna_seq_read_counts_Zscores","os_target_gdc_mrna_seq_tpm","os_target_gdc_mrna_seq_tpm_Zscores","os_target_gdc_mutations","os_target_gdc_rna_seq_mrna"],"heatmapProfileIds":["os_target_gdc_mrna_seq_fpkm_Zscores","os_target_gdc_mrna_seq_read_counts_Zscores","os_target_gdc_mrna_seq_tpm_Zscores"],"availableComparisonTabs":["overlap","clinical","survival","alterations","mutations","mrna"]}}]}} ▶ navigate_to_results_view { "studyIds": [ "os_target_gdc" ], "genes": [ "TP53", "MUC16", "TTN", "ATRX", "DNAH9" ], "tab": "mutations" } ◀ result {"success":true,"message":"Navigating to https://www.cbioportal.org/results/mutations?cancer_study_list=os_target_gdc&gene_list=TP53%0AMUC16%0ATTN%0AATRX%0ADNAH9&case_set_id=os_target_gdc_all","url":"https://www.cbioportal.org/results/mutations?cancer_study_list=os_target_gdc&gene_list=TP53%0AMUC16%0ATTN%0AATRX%0ADNAH9&case_set_id=os_target_gdc_all","data":{"studyIds":["os_target_gdc"],"studies":[{"studyId":"os_target_gdc","name":"Osteosarcoma (TARGET GDC, 2025)","sampleCount":159}],"genes":["TP53","MUC16","TTN","ATRX","DNAH9"],"caseSetId":"os_target_gdc_all","pageDescription":"Detailed mutation table with lollipop plot showing mutation positions, types, and frequencies for queried genes."}} ═ answer (success) ## Top 5 Most Frequently Mutated Genes in TARGET Osteosarcoma **Study:** Osteosarcoma (TARGET GDC, 2025) — 143 samples profiled for mutations ### Results: | Gene | Altered Samples | Sample Frequency | Mutation Events | |------|-----------------|------------------|-----------------| | **TP53** | 32/143 | **22.4%** | 33 | | **MUC16** | 16/143 | **11.2%** | 17 | | **TTN** | 16/143 | **11.2%** | 18 | | **ATRX** | 11/143 | **7.7%** | 11 | | **DNAH9** | 10/143 | **7.0%** | 10 | **Key observations:** - **TP53** is the most frequently mutated gene in this osteosarcoma cohort at ~22%, consistent with TP53's known role in osteosarcoma pathogenesis - MUC16 and TTN are large passenger-prone genes with similar frequencies - ATRX and DNAH9 represent other recurrently mutated genes in this cohort [View detailed mutations and lollipop plots](https://www.cbioportal.org/results/mutations?cancer_study_list=os_target_gdc&gene_list=TP53%0AMUC16%0ATTN%0AATRX%0ADNAH9&case_set_id=os_target_gdc_all)