Abstract:
Background: Klinefelter syndrome (KS) is the most frequent chromosomal abnormality caused by aneuploidies. It occurs in 1/660 male newborns and has a prevalence of 1-2% in infertile men; 0.6% with severe oligospermia (<5 million sperm/ml) and 10-12% in patients with azoospermia.
Objective: To determine the prevalence of KS in patients with male infertility at the National Institute of Perinatology (INPer) and the prevalence of the main clinical characteristics of the syndrome, the hormonal profile and the diagnostic karyotype they presented.
Methodology: Patients with male infertility were included between 2016 and 2018 that presented azoospermia or severe oligospermia in semen analysis (SA) and had a karyotype as part of the diagnostic approach. The clinical characteristics, somatometry and initial hormonal profile were analyzed.
Results: A total of 1,029 men with male infertility were found between 2016 and 2018 with a prevalence of 0.29%; 100% presented azoospermia on SA with a 47, XYY karyotype. The average age of KS diagnosis was at 30.3 years, with a height of 1.66 m and BMI of 24.98 kg/m
2 (normal). 100% presented testicular hypotrophy with an average volume ​​of 2.68 cc and 2.49 cc (right and left respectively). Only one patient presented gynecomastia (33%) stage 3 in Tanner scale and one hypospadias (33%). The average on hormonal profile levels was 32.4 mIU/ml for FSH, 20.43 mIU/ml for LH, testosterone of 8.14 nmol/L and estradiol of 53.46 pg/ml. 100% had normal prolactin levels (8.27 ng/ml).
Conclusions: KS is one of the most common genetic causes of male infertility characterized by a 47, XXY karyotype. The main clinical manifestations are: tall stature, overweight and obesity, sparse hair, testicular hypotrophy (<4 cc), gynecomastia, and infertility. They are characterized by having abnormal concentrations of testosterone, FSH and LH and they can achieve pregnancy using TESE (Testicular Sperm Extraction) combined with ICSI.
