LDscore

LDscore refers to the linkage disequilibrium score, a metric used in genetics to quantify the extent to which two or more genetic loci are associated with each other. Linkage disequilibrium occurs when alleles at different loci are inherited together more often than would be expected by chance. The LDscore essentially measures the strength and extent of this non-random association. High LDscores indicate that alleles at nearby loci are frequently found together, suggesting they are physically close on the chromosome and likely to be inherited as a block. Conversely, low LDscores indicate that alleles at different loci are more independently assorted.

This measure is particularly important in genome-wide association studies (GWAS) and population genetics. In GWAS, LDscore is used to estimate heritability and genetic correlation between traits. It helps to infer the relationship between genetic variants and phenotypic traits by accounting for the correlation structure of genetic variation across the genome. By understanding the LD patterns, researchers can better interpret association signals and identify causal variants. LDscore calculations typically rely on genotype data from a reference panel that represents the population of interest. The score for a particular genetic locus is the sum of LD measures between that locus and all other loci within a specified window. This allows for a genome-wide assessment of linkage disequilibrium.