Table 2-9. Frequencies of some Rh genes.
(2) Rosenfield, et al. have proposed a nomenclature based entirely on
phenotypic observations. Antigens are numbered and their presence or absence on red
blood cells is designated by positive and negative numbers. Table 2-10 shows reaction
patterns for various cells tested with the five major antiserums, and the phenotypic
descriptive terms used in the three nomenclature systems.
c. Phenotype and Genotype.
(1) In clinical practice, only five reagent antiserums are readily available.
For most pre-transfusion studies, tests are performed only for Rho(D), while the other
antiserums are used principally in family studies or investigation of commonly
encountered antibodies. The assortment of antigens detectable on an individual's cells
is his phenotype. Since any individual antigen may be part of several different genetic
packages, it is not always possible to deduce which combination of genes has produced
a given phenotype.