molecular dissection using array comparative genomic hybridization and clinical evaluation of an infertile male carrier of an unbalanced y;21 translocation: a case report and review of the literature

chromosomal defects are relatively frequent in infertile men however, translocations between the y chromosome and autosomes are rare and less than 40 cases of y-autosome translocation have been reported. in particular, only three individuals has been described with a y;21 translocation, up to now. we report on an additional case of an infertile man in whom a y;21 translocation was associated with the deletion of a large part of the y chromosome long arm. applying various techniques, including conventional cytogenetic procedures, fluorescence in situ hybridisation (fish) analysis and array comparative genomic hybridization (array-cgh) studies, we identified a derivative chromosome originating from a fragment of the short arm of the chromosome y translocated on the short arm of the 21 chromosome. the y chromosome structural rearrangement resulted in the intactness of the entire short arm, including the sex-determining region y (sry) and the short stature homeobox (shox) loci, although translocated on the 21 chromosome, and the loss of a large part of the long arm of the y chromosome, including azoospermia factor-a (azfa), azfb, azfc and yq heterochromatin regions. this is the first case in which a (yp;21p) translocation has been ascertained using an array-cgh approach, thus reporting details of such a rearrangement at higher resolution.