Deletion of Y chromosome involving the DAZ (deleted in azoospermia) gene in XX males.
The testicular histology and the presence or absence of 32 Y DNA loci was investigated, with a focus on the long arm of Y chromosome (Yq) interval 6, by means of a polymerase chain reaction strategy in 2 XX males. Seminiferous tubules lined by only Sertoli cells and a slight thickening of tubular walls were observed. The men showed an absence of 32 Y DNA loci. These facts suggest that severe spermatogenic impairment is caused by deletions of Yq interval 6 in XX males.