Y Chromosome Microdeletions in Infertile Men with Non-obstructive Azoospermia and Severe Oligozoospermia

The purpose of the study was to investigate the frequencies and types of Y chromosome microdeletions in infertile men and to analyze the relationship between the levels of reproductive hormones and Y microdeletions.
A total of 1,226 infertile men were screened for Y chromosome microdeletions using multiplex PCR assay. Karyotype analysis was performed on peripheral blood lymphocytes with standard G-banding. Serum reproductive hormone levels were measured.
Out of 1,226 infertile patients, 134 (10.93%) had Y microdeletions. One hundred seven of 765 (13.99%) non-obstructive azoospermic patients and 27 of 133 (20.30%) severe oligozoospermic patients had Y microdeletions. Among the 134 infertile men with Y microdeletions, the most frequent microdeletions were detected in the AZFc region, followed by AZFbc, AZFb, AZFa, AZFabc(Yq), Yp(SRY), and partial AZFc regions. Karyotype analysis was available for 130 of the 134 patients with Y microdeletions. Of them, 36 (27.69%) patients had sex chromosomal abnormalities. Levels of FSH and LH in patients with AZFc microdeletion were significantly lower, while those in patients with Yp(SRY) were significantly higher than in patients without Y microdeletions. Level of testosterone in patients with AZFabc(Yq) or Yp(SRY) was significantly lower than that in patients without Y microdeletions. However, there was no significant difference in the levels of reproductive hormones between all patients with and without Y microdeletions.
These results highlight the need for Y chromosome microdeletion screening for correct diagnosis of male infertility. Obtaining reliable genetic information for assisted reproductive techniques can prevent unnecessary treatment and vertical transmission of genetic defects to offspring.