Admixture mapping

Admixture Mapping is a method used in genetics to study the genetic basis of differences in disease risk between populations. It is a powerful tool for identifying genetic variants that contribute to health disparities.

Overview

Admixture mapping, also known as mapping by admixture linkage disequilibrium (MALD), is a method of genetic mapping that makes use of a population of mixed ancestry (an admixed population) to find the genetic loci that contribute to differences in diseases or traits between the different ancestral populations. This method is particularly useful for studying complex diseases that have different prevalence rates in different populations.

Methodology

The basic principle of admixture mapping is to search for regions of the genome where the proportion of ancestry from one of the ancestral populations is higher than expected. This is done by comparing the observed ancestry in a sample of individuals with the expected ancestry based on the overall admixture proportion in the population. The method relies on the fact that, in an admixed population, individuals will have varying proportions of their genome derived from each of the ancestral populations.

Applications

Admixture mapping has been used to identify genetic variants associated with a variety of diseases and traits, including hypertension, diabetes, prostate cancer, and asthma. It has also been used to study the genetic basis of differences in drug response between populations.

Limitations

While admixture mapping is a powerful tool, it also has limitations. These include the need for large sample sizes, the requirement for accurate estimates of individual ancestry, and the potential for confounding by population stratification.

See also

• Genetic linkage
• Genome-wide association study
• Population genetics