296 



Blood Groups 



blastotic child, was tested, the serum was found to contain an 

 antibody which could agglutinate all Rh-negative bloods. This 

 new property was designated Hr and the corresponding agglu- 

 tinin anti-Hr. A similar agglutinin was reported in 1943 by 

 Race and Taylor in England who designated it the St factor. 

 Levine and Javert, however, had apparently used a weak anti- 

 serum which gave only about 30 per cent positive reactions, 



TABLE 15 



The Eight Rhesus Blood Types Akranged to Show That They Fall 

 INTO Four Classes with Respect to Their Reactions to Anti-Rh' 



AND Anti-Rh" Sera 



• (Modified slightly from Wiener, Sonn, and Belkin in the Journal of 



Experimental Medicine.) 



* Among whites in New York City. 



Each class can be divided into two subclasses based on the reaction to anti-Rho sera. 



whereas Race and Taylor's serum was stronger and gave about 

 80 per cent positive reactions. That the same property was 

 present in the two factors and that both should be called Hr 

 was pointed out by Wiener, Davidsohn, and Potter who suggested 

 that the weak antiserum of Levine failed to test blood which 

 was heterozygous for the Hr factor. 



The Hr factor in the blood is apparently not the result of a 

 new gene but is a property of genes r, r^, W^ , and R^, for it is 

 found in the agglutinogens determined by each of those genes. 

 On the other hand, genes R^ and R^ do not appear to result in 

 the production of the Hr factor for the agglutinogens determined 

 by these two genes do not contain this Hr factor. If Wiener's 

 assumption is correct that a stronger reaction with anti-Hr serum 



