Ncbi Gene

NCBI Gene Database

Overview

NCBI Gene is a comprehensive database integrating gene information from diverse species. It provides nomenclature, reference sequences (RefSeqs), chromosomal maps, biological pathways, genetic variations, phenotypes, and cross-references to global genomic resources. In this project the agent exposes 3 download tools: fetch gene data by ID or symbol (Datasets API), and batch lookup by symbols. For finer control, ncbi_operations.py also provides E-utilities download/query functions (esearch, esummary, efetch) and additional batch operations. All download/query functions return rich JSON {status, file_info/content, content_preview, biological_metadata, execution_context}.

When to Use This Skill

This skill should be used when working with gene data including searching by gene symbol or ID, retrieving gene sequences and metadata, analyzing gene functions and pathways, or performing batch gene lookups.

Quick Start

The skill provides:

1. Project modules in src/tools/database/ncbi/: fetch_gene_data.py (Datasets API), query_gene.py (E-utilities), batch_gene_lookup.py (batch operations), ncbi_operations.py (query/download operations); gene download functions re-exported via package.
2. References: references/api_reference.md, references/common_workflows.md

NCBI provides two main APIs:

• Datasets API — Optimized for gene data retrieval; used by download_ncbi_gene_by_id and download_ncbi_gene_by_symbol tools
• E-utilities — Full-featured API for complex queries; used by the esearch/esummary/efetch programmatic functions

Agent Tools (Download Only)

Also available as general NCBI tools (useful in gene workflows):

Project Modules (Programmatic Use)

Core Capabilities

1. Download Gene by ID (Datasets API)

from src.tools.database.ncbi import download_ncbi_gene_by_id

result = download_ncbi_gene_by_id("672", "output/ncbi_gene_brca1.json")
# Returns rich JSON with gene metadata, RefSeqs, GO annotations, etc.

2. Download Gene by Symbol (Datasets API)

from src.tools.database.ncbi import download_ncbi_gene_by_symbol

result = download_ncbi_gene_by_symbol("BRCA1", "human", "output/ncbi_gene_brca1_by_symbol.json")
result = download_ncbi_gene_by_symbol("TP53", "Homo sapiens", "output/ncbi_gene_tp53.json")

3. Batch Lookup by Symbols

from src.tools.database.ncbi import download_ncbi_batch_lookup_by_symbols

result = download_ncbi_batch_lookup_by_symbols(
    ["BRCA1", "TP53", "EGFR"], "human", "output/ncbi_genes_batch.json"
)

4. E-utilities Workflow (programmatic)

from src.tools.database.ncbi.ncbi_operations import (
    query_ncbi_gene_esearch,
    download_ncbi_gene_esummary,
    download_ncbi_gene_efetch,
)

# Step 1: Search for gene IDs
esearch_result = query_ncbi_gene_esearch("BRCA1[gene] AND human[organism]", retmax=10)

# Step 2: Download summaries or full records
download_ncbi_gene_esummary(["672", "7157"], "output/gene_summaries.json")
download_ncbi_gene_efetch(["672"], "output/gene_full_record.xml")

5. Low-Level Direct Access (programmatic)

from src.tools.database.ncbi.fetch_gene_data import fetch_gene_by_id, fetch_gene_by_symbol
from src.tools.database.ncbi.query_gene import esearch, esummary, efetch
from src.tools.database.ncbi.batch_gene_lookup import batch_lookup_by_symbols

# Datasets API
gene_data = fetch_gene_by_id("672")
gene_data = fetch_gene_by_symbol("BRCA1", "human")

# E-utilities
gene_ids = esearch("insulin[gene] AND human[organism]")
summaries = esummary(gene_ids)
records = efetch(gene_ids, retmode="xml")

# Batch
results = batch_lookup_by_symbols(["BRCA1", "TP53"], "human")

Common Workflows

Workflow 1: Gene Annotation (download)

from src.tools.database.ncbi import (
    download_ncbi_gene_by_symbol,
    download_ncbi_batch_lookup_by_symbols,
)

# Single gene
download_ncbi_gene_by_symbol("BRCA1", "human", "output/brca1_annotation.json")

# Gene panel
download_ncbi_batch_lookup_by_symbols(
    ["BRCA1", "BRCA2", "TP53", "PTEN", "ATM"], "human", "output/cancer_panel.json"
)

Workflow 2: Gene Search and Retrieve (programmatic)

from src.tools.database.ncbi.ncbi_operations import (
    query_ncbi_gene_esearch,
    download_ncbi_gene_by_id,
)
import json

# Search by complex query
result = query_ncbi_gene_esearch("p53 AND human[organism]", retmax=5)
parsed = json.loads(result)

# Download details for each hit
if parsed.get("status") == "success":
    content = json.loads(parsed["content"])
    for gene_id in content.get("gene_ids", []):
        download_ncbi_gene_by_id(str(gene_id), f"output/gene_{gene_id}.json")

Workflow 3: Cross-Database Integration

from src.tools.database.ncbi import (
    download_ncbi_gene_by_id,
    download_ncbi_sequence,
    download_ncbi_metadata,
)

# Step 1: Get comprehensive gene info
download_ncbi_gene_by_id("672", "output/brca1_gene_info.json")

# Step 2: Download protein sequence
download_ncbi_sequence("NP_009225.1", "output/brca1_protein.fasta", db="protein")

# Step 3: Download GenBank metadata
download_ncbi_metadata("NP_009225.1", "output/brca1_metadata.gb", db="protein")

Search Query Patterns

Example E-utilities query patterns for NCBI Gene:

• Gene symbol: insulin[gene name] AND human[organism]
• Gene with disease: dystrophin[gene name] AND muscular dystrophy[disease]
• Chromosome location: human[organism] AND 17q21[chromosome]
• GO term: GO:0006915[biological process] (apoptosis)
• Phenotype: diabetes[phenotype] AND mouse[organism]
• Pathway: insulin signaling pathway[pathway]

API Access

Rate Limits:

• Without API key: 3 requests/second for E-utilities, 5 requests/second for Datasets API
• With API key: 10 requests/second for both APIs

Authentication: Register for a free NCBI API key at https://www.ncbi.nlm.nih.gov/account/ to increase rate limits.

Data Formats

NCBI Gene data can be retrieved in multiple formats:

Best Practices

1. Always specify organism when searching by gene symbol to avoid ambiguity
2. Use Gene IDs for precise lookups when available
3. Batch requests when working with multiple genes to minimize API calls
4. Cache results locally to reduce redundant queries
5. Include API key in environment for higher rate limits
6. Handle errors gracefully with retry logic for transient failures

Resources

Helper Scripts

• fetch_gene_data.py — NCBI Datasets API: fetch_gene_by_id(), fetch_gene_by_symbol(), fetch_multiple_genes()
• query_gene.py — E-utilities: esearch(), esummary(), efetch(), search_and_summarize()
• batch_gene_lookup.py — Batch: batch_esearch(), batch_esummary(), batch_lookup_by_ids(), batch_lookup_by_symbols()

Reference Documentation

• references/api_reference.md — E-utilities and Datasets API documentation, endpoints, parameters, response formats
• references/common_workflows.md — Additional examples and use case patterns