A SURVEY FOR THE RARE BLOOD-GROUP ANTIGEN VARIANTS, EN(A-), GERBICH NEGATIVE AND DUFFY NEGATIVE ON ESPIRITU-SANTO, VANUATU IN THE SOUTH-PACIFIC

The people of Vanuatu exhibit several different genetic red cell polym orphisms. Some of these, such as alpha thalassaemia, are thought to ha ve reached a high frequency as a result of selection pressure by malar ia. In this study three rare blood group antigen variants, En(a-), Ger bich negative and Duffy negative, which are thought to confer a protec tive effect against malaria were sought in a sample of 214 (187 in the case of Duffy) from Espiritu Santo, Vanuatu. No individuals bearing t hese rare variants were found. The original settlers in Vanuatu are th ought to have migrated from Papua New Guinea some 5,000 years ago, so it is of interest to note that no individuals were found to be Gerbich negative despite a high frequency in Melanesians living on some coast al parts of Papua New Guinea.