Two individuals with the rare Ge:−2,−3,4 phenotype (Gerbich type of Gerbich negative) were identified in a family of Polynesian descent who reside in the Cook Islands. In initial serologic tests, all other family members typed as Ge-positive, and heterozygous individuals could not be identified. Further studies on blood samples from seven members of this Polynesian family by immunoblotting and hemagglutination tests on trypsin-treated red blood cells showed that normal glycophorin C and the prodUR of the Gerbich allele were inherited in an autosomal dominant manner.