FinnGen provides genetic insights from a well-phenotyped isolated population

Area of Science:

• Human Genetics
• Population Genetics
• Genomic Medicine

Background:

• Population isolates, like Finland's, concentrate deleterious alleles in low-frequency variants (0.1%–5% MAF).
• This phenomenon, well-established in Mendelian genetics, is less explored for common diseases.
• The FinnGen study leverages genomic and health register data from a large Finnish cohort.

Purpose of the Study:

• To investigate genetic associations with common diseases in the Finnish population using FinnGen data.
• To identify low-frequency variants contributing to disease risk.
• To explore the utility of population isolates in common disease genetics.

Main Methods:

• Genome-wide association studies (GWAS) on 224,737 FinnGen participants.
• Analysis of 15 common diseases previously studied using GWAS.
• Meta-analyses incorporating Estonian and UK biobank data.
• Phenome-wide association studies (PheWAS) across 1,932 diseases.

Main Results:

• Identified 30 novel genetic associations, predominantly low-frequency variants enriched in the Finnish population.
• Discovered 2,733 genome-wide significant associations at 2,496 independent loci across 807 endpoints.
• Fine-mapping implicated 148 coding variants linked to 83 endpoints, with 91 showing low frequency (<5%) in non-Finnish Europeans and significant enrichment in Finland.

Conclusions:

• Finnish population isolates provide a powerful resource for identifying low-frequency, high-impact variants in common disease genetics.
• The study demonstrates the value of bottlenecked populations for uncovering disease biology.
• FinnGen's findings offer new entry points into understanding the genetic architecture of common diseases.