ABSTRACT
PURPOSE: COVID-19 has worse clinical outcomes in males compared with females and testosterone may determine gender differences. Hypogonadism and supernumerary X chromosome may have a role in the SARS-CoV-2 infection in Klinefelter syndrome (KS). Aim of the study was evaluating COVID-19 frequency and severity in KS. METHODS: Participants were invited to complete a retrospective self-administered questionnaire containing multiple choice and open-ended answers. RESULTS: COVID-19 was detected in 10% of the evaluated KS subjects; none was hospitalized. 44.4% of COVID-19 patients had one cohabitant-infected versus 3% of non-infected (p < 0.01). Testosterone levels in infected patients were lower compared to those of non-infected subjects (3.1 ± 1.2 ng/ml vs. 5.2 ± 2 ng/ml, p < 0.05). CONCLUSIONS: The frequency of SARS-CoV-2 infection among KS subjects was 10%. All infected patients showed mild symptoms. The presence of one affected cohabitant significantly associated with SARS-CoV-2 infection. An association between SARS-CoV-2 and hypogonadism was confirmed.