The Rhesus story in Northern Ireland.

DISCOVERY OF THE RHESUS BLOOD GROUP For many years, doctors had realised that there was a heterogeneous group of newborn babies who developed jaundice, anaemia or both, which were variants of a single underlying disorder, characterised by haemolysis and erythroblastosis. In 1940, Landsteiner and Wiener ' published a paper of less than 20 lines in which they described the discovery of the Rhesus blood group system. In the following year Levine2 reported that haemolytic disease of the newborn or in some cases a stillbirth, was due to incompatibility between mother and fetus. The next developments took place in England where Fisher,3 working in Cambridge, predicted and later proposed an alternative notation to the Rh/hr suggested by Wiener. His CDE/cde notation is now accepted throughout the world. Coombs,4 working in the same laboratory, developed a technique for detecting Rhesus antibodies. This test is also used throughout the world. Seventeen per cent of women in the British Isles are Rhesus negative, and lack of this antigens is designated by the letters d/d. It has been calculated' that three of the seventeen will marry Rhesus negative husbands, six will marry homozygous Rhesus positive (D/D) husbands with a 1:12 chance of the second child being affected, while eight will marry heterozygous Rhesus positive (D/d) husbands with a chance of the second baby being affected in 1:15.