Fetching MR Data

Generate harmonized JSON data for Mendelian Randomization analysis

Zhang WJ. 2026. MR-GWAS-JSON: A web tool for multi-source Mendelian Randomization (MR) data fetching, harmonization, and JSON generation. Network Biology, 16(4): 403-488

Choose Your Workflow:

Option 1: Direct JSON Input

Already have harmonized JSON data? Paste it directly and you're done. Perfect for pre-processed datasets.

Option 2: File Upload & Harmonization

Upload exposure/outcome files (CSV, TXT, JSON, GZ), harmonize with correlation matrix from AI or public databases, get JSON output.

Option 3: AI and Multi-Source Solutions

Use AI to fetch GWAS data by trait names OR fetch real GWAS data from multiple databases (IEU OpenGWAS, GWAS Catalog, FinnGen, GWAS Atlas, eQTLGen).

Direct JSON Input

Paste your existing harmonized JSON data below:

Expected Format: JSON object with keys: snps (array), betaX, betaY, betaXse, betaYse (arrays), correlation (2D array), exposure, outcome (strings). Alternatively, you can directly edit the JSON data in the box.

File Upload & Harmonization

Upload your exposure and outcome files, then harmonize with correlation matrix:

Step 1: Upload Files

Click or drag to upload

CSV format: SNP,ea,nea,beta,se,eaf
JSON format: {"rs9939609": {"ea":"A","nea":"T","beta":0.15,"se":0.02}}

Click or drag to upload

CSV format: SNP,beta,se,ea,nea,eaf
JSON format: {"rs9939609": {"beta":-0.08,"se":0.03,"ea":"A","nea":"T"}}

Step 2: Harmonization & Correlation Matrix

Correlation Matrix Source: Choose between public genetic databases or AI-fetched correlation matrices. AI options (DeepSeek, Gemini) provide alternative correlation estimation. Public databases (NIH LDlink, 1000 Genomes, gnomAD) are free.
DeepSeek: Get API key (Free tier available)
Gemini: Get API key

AI and Multi-Source Solutions

Choose between AI fetched GWAS data or fetching from multiple databases:

Step 1: Analysis Configuration

For univariate analysis, enter one trait. For multivariate analysis, enter multiple traits separated by commas.

Step 2: AI Configuration for Data Fetching

DeepSeek: Get API key (Free tier available)
Gemini: Get API key
GPT: Get API key

AI is fetching GWAS data... This may take 30-60 seconds.

Step 2: Data Sources

Select one or more databases to search for GWAS summary statistics. Multiple sources increase the chance of finding relevant data.

Step 3: API Authentication (Optional)

Some databases may require authentication tokens for access or higher rate limits. Leave blank if not required.
SNPs with p-values below this threshold will be considered genome-wide significant.