Genome wide association studies

Many methods for associating variants with a phenotype, trait or disease rely on the fact that a variant leading to a phenotype is found at a higher frequency in cases (individuals with the phenotype) than controls (individuals without the phenotype).

Genome wide association studies (GWAS) involve genotyping individuals at common variants across the genome using genome wide SNP arrays. Variants associated with trait, or within the same haplotype as a variant associated with a trait, will be found at a higher frequency in cases than controls.

Statistical analysis is carried out to indicate how likely a variant is to be associated with a trait. The p-value of the association indicates how likely the variant is to be associated with the trait (Figure 14).

The GWAS Catalog is the primary resource of genotype-phenotype associations identified through genome-wide association studies. Learn more with the webinar recording Exploring genotype-phenotype data using the GWAS Catalog.