H–Y gene expression in apparent absence of the long arm of the Y chromosome

H-Y antigen expression was detected on cells from an individual having a presumptive 45,X/46,X,i(Yp) karyotype, but was absent on cells from another person having a 46,X,i(Yq) karyotype. This suggests that the short arm of the human Y chromosome is essential for H-Y antigen expression, at least in the subjects studied.