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dpsguy
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What is linkage disequilibrium in genetics? How is it different from linkage?
Monique said:It is linkage disequilibrium (LD), because you can predict the state of one marker if you know the state of the marker next to it (the markers that are used are SNPs). If something is in equilibrium, the distribution would be random.
contrio said:alright i was a bit off, sorry about that
dpsguy said:Thanks Monique! I think I get it now,more or less. I guess it would be correct to say that studying linkage can help us find the locus related to a given phenotype while LD helps us establish the gene or even a gene variant, in case of a mutation(?)
Linkage Disequilibrium, also known as LD, is a measure of the non-random association between two alleles at different loci on a chromosome. It occurs when two or more alleles are inherited together more often than would be expected by chance.
The terms Linkage and Linkage Disequilibrium are often used interchangeably, but they have different meanings. Linkage refers to the physical proximity of two or more genes on a chromosome, while Linkage Disequilibrium refers to the non-random association of alleles at those genes.
Linkage Disequilibrium can be caused by a variety of factors, including genetic drift, natural selection, and population admixture. It can also be caused by physical proximity of genes on a chromosome or by genetic linkage.
Linkage Disequilibrium is typically measured using a statistic called D, which compares the observed frequency of a particular combination of alleles to the expected frequency under random assortment. Other measures, such as r-squared (r2) and correlation coefficient (r), can also be used to quantify the strength of LD.
Linkage Disequilibrium plays a crucial role in many genetic processes, including genetic mapping, gene mapping, and genome-wide association studies. It can also provide insights into the evolutionary history of populations and can be used to identify regions of the genome that may be under selection or have undergone recent genetic changes.