Which theory postulates that the Rh system antigens were produced by three closely linked sets of alleles?

Which theory postulates that the Rh system antigens were produced by three closely linked sets of alleles?

• A. Fisher-Race
• B. Parker-Weinberg
• C. Landsteiner
• D. Haldane-Smith

Answer: (A)

The Rh antigen pattern is explained by three closely linked gene loci on the same chromosome—the D/d, C/c, and E/e pairs. Each locus contributes a specific antigen variant, and the combination present on a chromosome defines the Rh phenotype. Because these loci are tightly linked, they are usually inherited together as a single haplotype, so certain Rh antigen sets appear together across individuals. This idea is the Fisher-Race theory. It accounts for how the D, C/c, and E/e antigens are expressed in linked combinations on red cells. Other models exist historically, but the three-loci, tightly linked concept is the one described here.

The Rh antigen pattern is explained by three closely linked gene loci on the same chromosome—the D/d, C/c, and E/e pairs. Each locus contributes a specific antigen variant, and the combination present on a chromosome defines the Rh phenotype. Because these loci are tightly linked, they are usually inherited together as a single haplotype, so certain Rh antigen sets appear together across individuals. This idea is the Fisher-Race theory. It accounts for how the D, C/c, and E/e antigens are expressed in linked combinations on red cells. Other models exist historically, but the three-loci, tightly linked concept is the one described here.