THE INHERITANCE OF SPECIFIC ISO- 

 AGGLUTININS IN HUMAN BLOOD. 



By J. R. LEARMONTH. 



Student of Medicine, University of Glasgow. 



Introduction. 



The present enquiry arose out of work upon the clinical aspects of 

 transfusion of blood. In the course of this work, it became apparent 

 that it would be interesting to ascertain if the incidence of specific iso- 

 agglutinins in the blood, with the corresponding agglutinophilic reactions 

 of the red cells, obeyed in man the biological laws of Mendelian in- 

 heritance. No previous work upon this subject including a survey of 

 families could be found though a Mendelian interpretation has been 

 recently suggested by Hirschfeld and Hirschfeld (1919). In the following 

 report, a' series of observations upon forty families will be discussed on 

 these lines. 



History. 



In 1901, Landsteiner definitely showed that iso-agglutination re- 

 actions in human blood were not confined to individuals suffering from 

 disease, but that these reactions were also produced upon mixing the 

 bloods of normal people. This investigator classified human sera into 

 three gBoups, according to their iso-agglutinating action. Moss, in 1910, 

 as the result of further investigations, was able to add to these a fourth 

 group, and his classification of human sera is shown below in tabular 

 form. 



Red corpuscles agglutinated Serum agglutinates 

 Group by sera of groups R. B. C. of groups 



I II, III, IV — 



n III, IV I. Ill 



ni II, IV I, n 



IV — I, II, III 



The work of Moss has proved of great importance as a necessary pre- 

 liminary to blood transfusion, especially in the War. Prior to his 

 introduction of the group-compatibility tests, severe reactions after 

 transfusion were by no means uncommon. 



Journ. of Gen. x 10 



