Background and Objective: Microdeletions in the long arm of the Y chromosome account for approximately 6-8% of non-obstructive azoospermia cases and a smaller percentage of severe oligospermia cases. Identification of these microdeletions is of great importance in making treatment decisions for patients. The aim of this study was to determine the prevalence of deletions in this region in men with the aforementioned phenotypes living in northwest Iran, in order to determine the correct treatment method in the shortest possible time.

Methods:In the present study, 60 men with non-obstructive azoospermia (NOA) or severe oligozoospermia, who had been referred by specialists to the Medical Genetics Laboratory during 2023–2024, were initially subjected to cytogenetic testing and chromosomal analysis to assess karyotype integrity. Individuals with numerical or structural chromosomal abnormalities (n = 8) were excluded. The study was then continued with the remaining 52 participants who exhibited a normal karyotype. Detection of AZF microdeletions was performed using the Multiplex-PCR technique with three pairs of sequence-tagged site (STS) markers: sY84 and sY86 for AZFa, sY127 and sY134 for AZFb, and sY254 and sY255 for AZFc.

Results:Among the 30 patients with NOA and 22 patients with severe oligozoospermia, AZF microdeletions were identified in 6 individuals (11.53% of the total cohort). Of these, 4 were NOA cases and 2 were cases of severe oligozoospermia. Specifically, complete AZF deletions were observed in 1 patient (1.92%), AZFb deletions in 1 patient (1.92%), and AZFc deletions in 4 patients (7.69%). The individual with a combined deletion involving AZFa, AZFb, and AZFc, as well as the patient with an AZFb deletion and half of the AZFc-deleted individuals, presented with NOA. All cases of severe oligozoospermia associated with AZF deletions carried deletions in the AZFc region.

Conclusion:The findings of this study indicate that AZFc deletions represent the most prevalent type of AZF microdeletion in infertile men from northwestern Iran, with a substantial predominance over other types. Notably, isolated AZFa deletions and combined deletions involving AZFa,b; AZFa,c; or AZFb,c were not detected in this cohort. Overall, the results highlight the relatively high frequency of AZF deletions among infertile men and underscore the importance of incorporating targeted genetic testing into the diagnostic workup of NOA and severe oligozoospermia. Such testing facilitates timely diagnosis, minimizes unnecessary interventions, and enables the selection of more effective therapeutic strategies.