At the uppermost level of genomic analysis, methods such as LD-score regression (LDSC; Bulik-Sullivan et al., 2015a) have been developed to translate GWAS estimates into SNP-based heritability estimates for individual traits. SNP-based heritabilities are estimated using the entire set of summary statistics, and not just the statistically significant SNPs. These estimates are generally lower than those obtained from twin studies, in part because summary statistics include only common variants, while twin study estimates encompass all inherited variants. Current estimates for psychiatric disorders indicate that SNP-based heritability captures approximately 30-50% of the genetic variance estimated from twin studies (Baselmans, Yengo, Van Rheenen, & Wray, 2020).
