Y chromosome specific probes identify breakpoint in a 45,X/46,X,del(Y)(pter----q11.1:) karyotype of an infertile male.

An infertile male patient with a 45,X peripheral blood karyotype and a 45,X/46,X,del(Y)(pter----q11.1:) mosaic skin fibroblast karyotype is described. Steroid sulphatase (STS) activity was normal. Recombinant DNA studies using Y chromosome specific probes suggest that almost the entire long arm of the Y chromosome is deleted.