About PGC Risk

What is a polygenic risk score?

A polygenic risk score (PRS) estimates your genetic predisposition to a trait or condition by summing the effects of many genetic variants (SNPs) across your genome. Each individual variant has a small effect, but together they can indicate whether your overall genetic profile leans toward higher or lower risk compared to a reference population.

What is the PGC?

The Psychiatric Genomics Consortium (PGC) is the largest international consortium conducting genome-wide association studies (GWAS) for psychiatric disorders. Their studies have identified hundreds of genetic loci associated with conditions like schizophrenia, depression, bipolar disorder, and ADHD. The summary statistics from these studies form the basis for the scoring files used by this tool.

Why aren't these scores diagnostic?

Psychiatric PRS typically explain only a small percentage of the total variance in disease risk — often 1–10%. The remainder comes from environmental factors, life experiences, gene-gene interactions, rare variants not captured by common SNP arrays, and other complex biological mechanisms. A high PRS does not mean you will develop a condition, and a low PRS does not mean you won't.

What is LD clumping and why does it matter?

Linkage disequilibrium (LD) is the tendency for nearby genetic variants to be inherited together. Without LD clumping, correlated variants can be counted multiple times, inflating scores. Proper LD clumping requires a reference panel (like 1000 Genomes) and is computationally intensive. This tool does not perform LD clumping in v1 — scores are clearly labelled as "unclumped" and should be interpreted with this caveat in mind. Relative comparisons between your disorder scores remain informative.

Key PGC publications

Sullivan, P.F. et al. "Psychiatric Genomics: An Update and an Agenda." American Journal of Psychiatry, 2018.
Cross-Disorder Group of the PGC. "Genomic Relationships, Novel Loci, and Pleiotropic Mechanisms across Eight Psychiatric Disorders." Cell, 2019.
Wray, N.R. et al. "From Basic Science to Clinical Application of Polygenic Risk Scores." JAMA Psychiatry, 2021.

Privacy note: This tool runs entirely in your browser. Your DNA file is parsed locally and never sent to any server. Scoring files are downloaded once and cached in your browser's IndexedDB for subsequent use.