AZF gene microdeletions in azoospermic-oligozoospermic males

Abstract

Background and objective: The presence of microdeletions in the Y-chromosome azoospermia factor (AZF) region (YCMs) is considered the most frequent genetic cause of male infertility along with Klinefelter syndrome. The objective of this study was to investigate the frequencies and type of YCMs in infertile men in Aragon and to analyze the relationship between sex hormones, sperm count and microdeletions in them.

Patients and methods: Retrospective descriptive study of 644 men who during 2006-2019 were screened for YCMs using YChromStrip (Operón, Spain) by PCR+reverse hybridization, spermiogram, karyotype and quantification of sex hormones.

Results: The frequency of YCMs was 3.88% (25/644), not being detected in any patient with mild or normospermic oligozoospermia, that is, in sperm counts higher than 5×10⁶/mL. The group of azoospermic patients was the one that presented a higher frequency of YCMs (14.58%, 14/96). Deletions in the AZFc region were the most frequent (68%). 20% (5/25) of patients with YCMs also presented some type of karyotype abnormality that included aneuploidies, deletions, duplications and/or translocations. Sperm count was significantly lower and FSH and LH concentrations significantly higher in the group of patients with YCMs.

Conclusions: YCMs screening is a key test in the diagnostic approach to male infertility. Obtaining an adequate result allows choosing suitable assisted reproduction techniques, preventing unnecessary treatments and the transmission of genetic defects to offspring.

Keywords: Azoospermia; Hormonas reproductivas; Infertilidad masculina; Male infertility; Microdeleciones del cromosoma Y; Oligozoospermia; Reproductive hormones; Y-chromosome microdeletions.