High frequency of Klinefelter syndrome in a cohort of Sri Lankan males with non-obstructive azoospermia and oligozoospermia

Introduction: Klinefelter syndrome (KS) is the most common sex chromosomal aneuploidy. It affects 1:667 males. It is a major cause of male factor infertility due to the associated testicular atrophy. This study aims to describe the karyotype pattern identified in a cohort of Sri Lankan infertile males referred for cytogenetic testing prior to undergoing testicular biopsy. Materials and methods: The karyotype reports of males with severe oligozoospermia (sperm cell count<5×106 cells/ml in seminal fluid analysis) and non-obstructive azoospermia, who were referred for karyotyping between January 2010 and February 2019 were maintained prospectively in an anonymized database and analysed retrospectively. All patients were referred from a single urological practice prior to undergoing testicular biopsy. Karyotyping was performed on routinely cultured lymphocytes after GTG-banding according to the guidelines of the International System for Human Cytogenetic Nomenclature (2016). Results: A total of 69 infertile males underwent karyotyping. 40 (58.0%) had azoospermia and 29 (42.0%) had severe oligozoospermia. Abnormal karyotypes were seen in 14 (20.3%) males, comprising of 11 (78.6%) with KS (47,XXY) and 3 (21.4%) with 46,XX karyotype. Polymerase chain reaction for SRY gene was positive in one male with 46,XX karyotype. Among the KS patients, 6 (54.6%) had azoospermia and 5 (45.5%) had severe oligozoospermia. Conclusions: KS accounted for more than two-thirds of the chromosomal anomalies among the infertile males referred for karyotyping. These findings highlight the need for cytogenetic evaluation of severe oligozoospermic and azoospermic males prior to undertaking extensive invasive investigations and treatment measures in both partners.