Observations on the rare genes r′w and Rz of the Rh-Hr allelic series

Abstract

SummaryThe history of the development of knowledge of the Rh-Hr types is briefly reviewed, with special reference to the theory of multiple allelic genes. It is pointed out that this theory has been confirmed by numerous statistical studies of the Rh-Hr types in the population as well as extensive studies on families. In addition to corroborating the genetic theory, the newer studies have disclosed the great complexity of this blood group system, so that as many as 20 allelic genes have been identified up to the present time. In the case of the more common genes there is ample direct evidence to verify the genetic theory, but observations on the rarer blood types are necessarily limited, so that the validity of the genetic theory, as it pertains to the rarer Rh genes, is based mainly on analogy. In this paper, two unusual families are recorded, which illustrate the hereditary transmission of the rare agglutinogens rh′w and Rhz. These observations serve to justify the inference that the rarer Rh genes are subject to the same laws of heredity as the more common alleles of the Rh-Hr allelic series.