The Genetic Basis of Kidney Disease Risk in African Americans: MYH9 as a New Candidate Gene

Schematic of 1 chromosome pair from each of several individuals in an admixed population. A group of cases (for a given disease) and a group of controls are presented at the bottom left and the bottom right, respectively. For one of the control individuals (arrow), a schematic of all ancestors in the last 4 generations is shown in the upper part of the figure. In the first generation, mixing between population 1 (blue) and population 2 (red) occurs, generating offspring with red- and blue-origin chromosomes; in later generations, crossing over during meiotic recombination creates red/blue chimeric chromosomes. Admixture mapping can be ideally applied if populations 1 and 2 carry a different allele at the disease locus (dashed line). Whole-genome scanning under the admixture mapping strategy consists of scanning the genome and identifying the regions with an excess of “red” ancestry in the cases versus the controls, assuming that the “red” population carries the predisposition allele. Reproduced from Darvasi and Shifman²⁹ with permission.