Partition of the Antigen W16 into Two Subtypic Determinants

The partition of W16 into two subtypic determinants was suggested by its segregation with either W4(4a) or W6(4b) in families. It was confirmed by the serologic reactions of two antisera each of which recognized only one of its subtypic determinants. Gene frequencies of 0.01417 and 0.02711 were tentatively assigned to its W4 and W6 variants respectively.