Dicentric Y chromosome in azoospermic males.

Two azoospermic, infertile men with a pseudodicentric Y chromosome are reported. The small isodicentric Y chromosomes were composed of duplicated short arm and proximal long arm Y, as proven by fluorescence in situ hybridisation using a Y centromere-specific DNA probe, pDP97, and a short arm probe pY-80. Both lacked germinal cells in the gonads. It was assumed that the azoospermia was caused by deletion or disruption of the azoospermic factor gene located at distal Yq11. Patient 2 measured 147 cm (-4.1 SD) in height and so it was assumed that he had also lost the "statural determinants" gene.