Rapid screening of the Y chromosome in idiopathic sterile men, diagnostic for deletions in AZF, a genetic Y factor expressed during spermatogenesis.

A rapid molecular screening programme has been established for the long arm of the human Y chromosome in Yq11 in order to quickly detect small interstitial deletions in this chromosome region. They have been observed in idiopathic sterile males with azoospermia and a severe oligozoospermia and are therefore indicative for deletion of AZF gene sequences. AZF (i.e. azoospermia factor) is a genetic factor located in Yq11 which controls human spermatogenesis. The screening programme is based mainly on a multiplex PCR approach using a series of Y-specific primers amplifying single DNA loci in Yq11. The order of all Y-DNA loci can be unequivocally arranged along the whole long Y arm. Therefore, any detected deletion can be quickly mapped in relation to the proposed position of AZF. Benefits and pitfalls of this new diagnostic Y screening method will be discussed.