Heredity of Rh Blood Types. V. Improved Nomenclature; Additional Family Studies with Special Reference to Hr

Abstract

Further to simplify the notations of the Rh-Hr types, the 8 Rh blood types are now designated as rh, Rh'', Rh", Rh'' Rh", rh0, Rh1, Rh2 and Rh1Rh2, respectively. To prevent ambiguity between the names of the phenotypes and genotypes, in the notations for the genes the letter "h" is omitted and only superscripts and italics are used; thus, the 6 standard Rh genes are now designated as r, R'', R", r[degree], R1 and R2, respectively. When the known Hr factors, Hr'' and Hr", are taken into account, the number of types is increased from 8 to 12. With the aid of anti-Hr'' serum, type Rh1 is divided into subtypes Rh1Rh1 and Rh1rh and type Rh'' into subtypes Rh''Rh'' and Rh''rh; anti-Hr" serum permits a similar subdivision of types Rh2 and Rh". Besides their simplicity and lack of ambiguity, the new notations have the advantages that they take into account the known serologic and genetic facts concerning the Rh-Hr types and conform with the accepted practice of geneticists, while they avoid the introduction of any new symbols or letters like C, D and E, which are entirely foreign to the scheme of 12 Rh-Hr types. Investigations on the hereditary transmission of 8 Rh blood types in 300 families with 620 children yielded results in conformity with Wiener''s theory of 6 major allelic genes. Studies on the Hr factor in 81 families with 126 children and on a random series of 645 Caucasians in New York City fully support the theory that factors Rh'' and Hr'' are related to each other genetically and serologically like the ag-glutinogens M and N.