Prevalence and Spectrum of Chromosomal Abnormalities in 1366 Infertile Tunisian Men: A retrospective observational study

INTRODUCTION: Chromosomalabnormalities are a well-documented cause of male infertility, particularly in patients with severe sperm defects such as azoospermia. AIM: To assess the prevalence and types of chromosomalabnormalities in infertile men referred for cytogenetic analysis over a 19-year period, and to explore genotype-phenotypecorrelation. METHODS: Were trospectively analyzed 1366 karyo types performed between 2006 and 2024 in patients with abnormal semen parameters, referred at the Genetics Department of Charles Nicolle Hospital in Tunis for genetic investigations. Data were collected from medical records and laboratory reports. Standard karyotypingwasperformed in all cases, supplemented by fluorescence in situ hybridization (FISH) and Y chromosome microdeletion analysis when indicated. RESULTS: A total of 117 chromosomalabnormalities were identified among the 1366 infertile men, corresponding to a global prevalence of 8.5%. The most frequent clinical presentation was azoospermia, accounting for 60.3% of patients with chromosomalabnormalities. Numerical chromosomalabnormalities accounted for 80.3% (n = 94) of all detected cases. The most prevalent was Klinefelter syndrome, foundin 85 patients, representing 72.6% of all anomalies. Among patients with Klinefelter syndrome, 96.4% had non-obstructive azoospermia. Structural abnormalitieswereobservedin 23 patients (19.6%), comprisingbalanced translocations, inversions, Robertsonian translocations, and unbalancedchromosomal anomalies such as Yqdeletions and supernumerary marker chromosomes. CONCLUSION: Cytogenetic abnormalities were detected in nearly 8.5% of infertile men. Thesefindings support the utility of systematickaryotype.