Prevalence of Abnormal Karyotypes among Males with Non-obstructive Azoospermia and Severe Oligozoospermia: A Retrospective Study

Abstract

Introduction: Chromosomal abnormalities are one of the important causes of male infertility. Numerical and structural chromosomal abnormalities are seen frequently in men with azoospermia and severe oligospermia. Other abnormalities include Y Chromosome Microdeletions (YCMD), Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene mutations affecting the internal ductal system, genes affecting sperm function and other non-specific disorders. Upto 14% of the men with azoospermia and severe oligospermia have karyotypic abnormalities. Aim: To determine the prevalence of abnormal karyotypes among men with azoospermia and severe oligozoospermia (<5 million/mL). Materials and Methods: The present study was a retrospective observational study carried out at the Fertility Clinic, Institute of Maternal and Child Health, Calicut, Kerala, India, on patients who attended the Infertility Department between January 2016 to December 2019. Semen analysis was done on 232 patients with 100 patients of azoospermia and 132 patients of oligozoospermia. Karyotyping was done from the Cytogenetics Unit, Department of Anatomy. The data was entered in MS excel sheet and analysed and results were expressed in percentage. Results: Chromosomal abnormalities were detected in 35 (35%) of 100 azoospermia and 15 (11.3%) of 132 severe oligospermia cases analysed. Klinefelter syndrome was the most common abnormality detected in azoospermia (22/35). A 46XX was found in two cases. Structural abnormalities were detected in three case (46 X, der X, 46XY der Chr 1 and Chr 9 inversion). Small Y was found in three cases. Polymorphic variants were found in five patients (46XY 15pstk+, 46XY 15ps+, 46XY 1qh+, 46XY 9qh+). Small Y was found in one case. In oligozoospermia, autosomal translocations were found in four cases {46XY, t(11;13)(q21;q21.2), 46XY, t(1;9) (p13;p21), 46XY, t(13;15)(q34;q21), 46XY, t(7,14) (q34:q11)}, Derivative (46XY der 15) and Marker chromosome (47XY+mar) in one case each. Klinefelter syndrome was found in two cases and 48XXYY was found in one patient. Polymorphic variants were found in five cases (46XY 21pstk,46XY 15ps+, 46XY 1qh-, 48XY 9qh+). Small Y was found in one case. Conclusion: Sex chromosomal and autosomal abnormalities are found frequently in azoospermia and severe oligospermia and hence, genetic screening and counseling before Intracytoplasmic Sperm Injection (ICSI) is warranted.