Screening for partial AZFa microdeletions in the Y chromosome of infertile men: is it of clinical relevance?

Abstract

Objective: To evaluate the frequency of complete and partial AZFa Y-chromosome microdeletions among infertile Israeli men. To review the published frequencies and histologic findings of AZFa deletions.

Design: Retrospective study.

Setting: Academic medical center.

Patient(s): A total of 1,260 infertile Israeli men. Literature review (2000-2010) of reports on men with AZFa deletions and their testicular findings.

Intervention(s): The DNA of 1,260 infertile men was evaluated for AZF microdeletions. The DNA of 657 of them with undetected microdeletions was analyzed for partial AZFa deletion in the USP9Y and DDX3Y genes using sequence-tagged sites beyond EAA/EMQN recommendations.

Main outcome measure(s): The frequency of complete and partial AZFa microdeletions. Availability of sperm cells for intracytoplasmic sperm injection in men with complete/partial microdeletions.

Result(s): Two men had complete AZFa deletion (a frequency of 0.28% among nonobstructive azoospermic men). None had partial AZFa deletions.

Conclusion(s): The likelihood of finding sperm cells in men with complete AZFa deletions is negligible. Complete AZFa deletion is rare and usually associated with azoospermia and absence of sperm cells in testicular tissue. The low frequency of partial AZFa deletions and the inconsistent prospects for spermatogenesis reported in the literature question the need for routine assessment of microdeletions in genes, such as USP9Y or DDX3Y.