Eve B. Sonn

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

Summary New additions to and further simplifications of the designations of Rh blood types, subtypes and genes are proposed in order to encourage the more general use of the Rh and Hr tests by medical men and geneticists. Investigations on the hereditary transmission of the 8 Rh blood types in 300 families with 620 children yielded results in conformity with the 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 agglutinogens M and N.

THE Rh SERIES OF GENES, WITH SPECIAL REFERENCE TO NOMENCLATURE

Although only five years have elapsed since the Rh factor was first described by Landsteiner and Wiener,l this aspect of individual differences of human blood has developed into a complex subject, with important applications in clinical medicine, anthropology, and forensic medicine. In fact, the subject of the Rh factors appears to exceed, in complexity, all previously obtained knowledge concerning individual differences in human blood,? including the original four Landsteiner blood groups, the sub-groups of A and AB, and the M, N, and P agglutinogens of Landsteiner and Levinc. In place of the original, single Rh factor, transinittcd by a pair of allelic genes, Rh and rh, three Rh factors are known a t the present time, together with a so-called Hr factor, and these, in combination, give rise to a large series of different varieties of Rh agglutinogens, determined by a corresponding set of at least ten or more allelic genes. If any progress is to be made, or even if any work a t all is to be possible, i t is necessary to designate the Rh factor in some way. Therefore, as soon as sufficient evidence had been accumulated concerning the serologic and genctic behavior of the Rh factors, we devised a nomenclature, based on these firmly established serologic and genetic facts. Since the original designations have already been widely adopted and have proved satisfactory, becausc they are relatively simple to learn and work with, i t would appear that no change should be made, a t lcast for the time being, unless such a change offered a distinct ntlvantagt. IJnfortunatrly, Iiowever, R number of other workers have recently proposed other liwthods of designation. As will be shown, the alternative designations tlint have been proposed have no special advantage, but can only give rise to confusion in an already complicated subject. As long as the serologic and gcneticb behavior of the Rh factors remained unclear, the only sensible procedure was to use a temporary system of numbering for the various anti-Rh sera, and that was our procedure in our earliest publications. However, as soon as increased