H-Y typing by ELISA in a 46,X,dic(Y)(q11.2101) male: effects of a nonmosaic Yp duplication.

A new ELISA was used to measure H-Y antigen in cultured fibroblasts from a male with 46,X,dic(Y)(q11.2101) involving duplication of Yp. Aliquots of monoclonal H-Y antibody were absorbed with 1, 2, 4, or 8 X 10(6) cells from the 46,X,dic(Y) male, or with corresponding numbers of cells from a normal XY male and a normal XX female, and then were tested for residual activity against a soluble antigen source. Portions of the antibody absorbed with cells of the 46,X,dic(Y) male were found to be less reactive than portions absorbed with cells of the normal XY male, for all numbers of cells and both dilutions of plated antigen. The results, quantified in an electronic optical density reader, imply presence of excessive H-Y in cells of the 46,X,dic(Y) male, and suggest presence of a genetic determinant of H-Y on Yp or proximal Yq near the centromere.