Another early theory was that of the American Dr. Alexander Wiener. Wiener's theory is that Rh inheritance is controlled as follows:
For example, one gene R1 produces one agglutinogen (antigen) Rh1 which is composed of three "factors": rh', Rh(o), and hr''. The three factors are analogous to C, D, and e respectively in the Fisher-Race nomenclature. Alleles of the one gene could be R2 (cDE in Fisher-Race), Ro (cDe in Fisher-Race), etc. The d gene does not exist in Wiener's theory.
Note: The main difference between the Fisher-Race and Wiener theories is that whereas the Fisher-Race theory has three closely linked loci, the Wiener theory has only one gene locus at which multiple alleles occur.