variant-analysis-tools

Analyze VCF/BCF files to summarize, filter, and triage genetic variants.

126|8|Updated Mar 10, 2026
One-click install
npx skills add https://github.com/DrugClaw/DrugClaw --skill variant-analysis-tools
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: variant-analysis-tools
Source: https://github.com/DrugClaw/DrugClaw/tree/main/skills/genomics/variant-analysis-tools
Command: npx skills add https://github.com/DrugClaw/DrugClaw --skill variant-analysis-tools

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill requires pysam, and includes scripts (resource) and references (resource) components.

What problem does it solve?

This Skill provides a streamlined process for analyzing variant call files (VCF/BCF), enabling users to summarize, filter, and triage genetic variants locally before complex downstream analysis.

Core Features & Use Cases

  • Variant Summarization: Get counts of SNVs, indels, and structural variants.
  • Filtering: Apply filters based on variant allele frequency (VAF), read depth, PASS status, and consequence.
  • Gene/Consequence Triage: Identify top affected genes and filter out specific variant consequences (e.g., intronic).
  • Use Case: Inspect a VCF file to count mutation classes, filter variants with a VAF below 5%, and summarize the top affected genes.

Quick Start

Run the variant report script to analyze 'cohort/sample.vcf.gz' for the 'TUMOR' sample, keeping only PASS variants with a minimum VAF of 0.05 and depth of 20, excluding intronic consequences, and saving the output to 'variants/sample_filtered.csv' and 'variants/sample_filtered.json'.

Frequently Asked Questions about variant-analysis-tools

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I filter VCF files by variant allele frequency and read depth?

Variant analysis of VCF files involves summarizing counts of SNVs, indels, and structural variants. This Skill automates the process locally, parsing VCF/BCF files to generate counts of mutation classes and identify top affected genes for consequence triage.

Can I use pysam to parse BCF files for local variant triage?

Yes, you can use pysam to parse BCF files locally because this Skill requires pysam for VCF/BCF parsing. It processes the files in a Python 3 environment to triage genetic variants by consequence, such as excluding intronic variants, before downstream analysis.

What's the best way to summarize top affected genes from a VCF file?

You need a Python 3 environment and the pysam module installed to run this Skill. These prerequisites enable the local parsing of VCF and BCF files required to execute filtering, variant summarization, and consequence triage tasks.

Does this variant analysis approach support structural variants and indels?

After completing variant filtering and triage, you can use the generated CSV reports and JSON summaries for downstream analysis. These output formats facilitate data export, visualization, and integration into broader genomics pipelines for further biological interpretation.

Why does my VCF filtering exclude specific variant consequences like intronic variants?

For prerequisite setup, install Python 3 and pysam to enable local VCF/BCF file parsing, producing a ready-to-analyze sample dataset that meets the minimum depth and VAF threshold requirements.

Do I need a Python 3 environment to run VCF filtering and variant triage?

For complementary analysis, use bioinformatics scripts to cross-reference filtered variant CSV reports with genomic reference datasets, producing annotated consequence summaries for targeted gene triage.