ABSTRACT
<p><b>OBJECTIVE</b>To analyze the characteristics of azoospermia factor(AZF) deletions in Y-chromosome.</p><p><b>METHODS</b>Based on the AZF microdeletion screening on 272 cases of azoospermia and 240 cases of severe oligozoo spermia, 49 cases were investigated using 23 sequence-tagged sites (STS) in AZFa, AZFb and AZFc. For some cases, single nucleotide rarians (SNV) method was applied to identify the single nucleotide polymorphism (SNPs) in four DAZ gene copies and to determine the copy number of the DAZ gene.</p><p><b>RESULTS</b>In 6 cases with deletions of AZFb+c, there was 1 case with sY98/sY1206 deletion, 4 cases with P5/distal-P1 recombination and 1 with P4/distal-P1 recombination. In 3 cases with deletions in AZFb, 1 case showed P5/P3 deletion and 2 cases showed P5/proximal-P1 recombination with DAZ1 and DAZ2 deletions. b2/b4 recombination was observed in all the 40 cases with deletions in AZFc. A fraction of patients with AZFb and AZFb+c deletions showed oligospermia and spermatogenic failure by testicular biopsy.</p><p><b>CONCLUSION</b>Breakpoint localization of deletions in AZF regions may help elucidating the mechanisms of microdeletions, and analysis of the characteristics and quantity of deleted genes essential for normal spermatogenesis may evaluate the association of phenotype with spermatogenic failure.</p>