Objective: To evaluate the frequency of microdeletions in the long arm of Y chromosome of idiopathic infertile males with azoospermia and oligospermia in Shaanxi province in China and to investigate the relevance of sperm count to Y microdeletion frequencies.
Methods: According to the sequence of sequence-tagged sits (STS) AZFa, AZFb, AZFc and SRY, 4 of the azoospermic factor regions on Y chromosome long-term supplied by GenBank, 5 sets of primers were synthesized. The Y microdeletions in AZF regions were screened by polymerase chain reaction (PCR) in 64 idiopathic cases of azoospermia and oligospermia and 20 men of known fertility.
Results: No microdeletion was detected in the 20 normospermic subjects. Deletion of the AZFc/DAZ was detected in 11 individuals and one patient had both AZFb and AZFc deletion; no deletion of AZFa and SRY region was found. The frequency of Y microdeletions in the subgroups with different sperm count showed the highest value among azoospermic men (3 cases, 21.4%). The percentage progressively decreased with the deletion frequency (20.0%, 17.9% and 8.3%) in the subgroups with sperm counts of < 1 x 10(6)/ml, < (1-5) x 10(6)/ml and < (1 to approximately 10) x 10(6)/ml, respectively.
Conclusion: Y chromosome microdeletions are specifically associated with severe spermatogenic failure. The rate of deletion involving AZF region of the Y-chromosome is higher in infertile men with azoospermia and oligospermia. PCR amplification of AZF locus is useful for the diagnosis of microdeletions in the Y-chromosome.