Endocrine Abstracts

Introduction: Within the high prevalence of male infertility there is the rare 45,X/46,XY mosaicism, associated or not with hypogonadism. The phenotypes of this genetical disorder present with a wide variability ranging from Turner stigmata to apparent normal male.

Case report: Two men who presented with azoospermia in the context of couple infertility were subsequently found to be affected by 45,X/46,XY mosaicism. Physical examination revealed a complete different phenotype; case 1 presented with normal weight and short stature, whereas case 2 presented with abdominal obesity and normal height. Case 2 had also bilateral gynecomastia, micropenis and a history of monolateral gonadectomy for criptorchidism at puberty. Both cases presented with small and soft testes, decreased bone mineral density and perceptive hearing loss at audiometric testing. No cardiorenal alterations were found. Assessment of gonadal function showed an increase of LH and FSH with normal testosterone levels (3.5 ng/ml) in case 1 and low testosterone levels in case 2 (2.2 ng/ml). A state of glucose intolerance with normal insulin levels at baseline (4.0 μU/ml) and after glucose load (peak: 37 μU/ml) was found in case 1, whereas case 2 had normal glucose tolerance, basal hyperinsulinemia (19 μU/ml) but normal insulin response to glucose load (peak: 77 μU/ml). The lipid profile was normal with unexpected high HDL-cholesterol levels (case 1: 78 mg/dl; case 2: 61 mg/dl). Cytogenetic examination revealed a different prevalence of 46,XY cells between case 1 and 2. Structural Y chromosome abnormalities were found in both: 45,X/46,X,idic(Y) (pter->q12::q12->pter) in case 1; 45,X/46,Xinv(Y)(q.11.2q12) in case 2.

Conclusion: Assessment of karyotype should be a key part of the initial evaluation of male patients with azoospemia regardless of the phenotype. The prevalence of 46,XY cells and the presence of Y rearrangements should always be evaluated for the potential explanation of different phenotypes, including comorbidities.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.