ABSTRACT
More specific genetic investigations can be done if indicated, especially when the azoospermia or oligozoospermia is part of a more complex disease or syndrome. Although currently not offered on a routine basis for patients with azoospermia or oligozoospermia, next-generation sequencing will be implemented in the near future. Since then, many chromosomal studies have been performed in series of infertile males, and the conclusions drawn from these studies are that constitutional chromosomal aberrations increase as sperm counts decrease. This can be explained by the absence of the long-arm of the Y chromosome containing the azoospermia factor regions in XX males. In a few exceptional cases, fertility has been described in AZFc-deleted fathers who transmitted the deletion to their now-infertile sons. CBAVD had also been observed in 1%-2% of apparently healthy infertile males, and in 6%-10% of men with obstructive azoospermia.
