The Clinical Manifestation and Genetic Evaluation in Patients with 45,X/46,XY Mosaicism

Abstract

45,X/46,XY mosaicism is a rare chromosomal abnormality and probably underdiagnosed. Although clinical and genetic analyses have been performed in some disorders of sexual development, there have been few studies focusing on the phenotype and genetic details of 45,X/46,XY mosaicism, especially in the Chinese population. The aim of this study was to describe the experience of our service in relation to 16 cases with 45,X/46,XY mosaicism. The age at the first evaluation of the patients ranged from 43 days to 30 years. Eight patients were reared as female and 8 as male. The main reasons for examination were primary amenorrhea, sterility, or ambiguous genitalia. Short stature was more common in female than in male patients. Two patients accepted gonadectomy due to tumor risk and none presented gonadal malignancy. The SRY gene was amplified positively in all of the patients. AZF gene microdeletions were present in 6 of 8 male patients, and all adult male patients had no sperm. No correlation has been found between clinical manifestations and the proportion of mosaic cells in peripheral blood. Our observations may permit a better management of people with 45,X/46,XY mosaicism.

Clinical but Not Histological Outcomes in Males With 45,X/46,XY Mosaicism Vary Depending on Reason for Diagnosis

“…However, almost 20% did produce semen samples with live spermatozoa. Both findings are in accordance with previous studies reporting low or no fertility in patients with 45,X/46,XY mosaicism (6,12,26,39). It is important to note that the males with live spermatozoa in this study were diagnosed at different ages from birth into adulthood and with varying degrees of genital androgenization.…”

“…However, gonadotropin levels were relatively high indicative of some degree of (early) gonadal failure. Altogether, our findings are in accordance with previous reports on gonadal function in males with a 45,X/46,XY karyotype (5,7,10,16,26).…”

Recognition and management of adults with Turner syndrome: From the transition of adolescence through the senior years

“…Mosaicism involving 45,X/46,XY can be associated with a spectrum of phenotypes ranging from typical female (with a low proportion of 46,XY) or typical male (with a low proportion of 45,X), to males with hypogonadism or ambiguous genitalia. For this reason, the term “male Turner syndrome” should be avoided, and individuals can be referred to as having mixed gonadal dysgenesis, or simply mosaicism for 45,X/46,XY (Lindhardt Johansen et al, ; Nomura et al, ; Wu et al, ).…”

Successful surgical sperm retrieval from a patient with 45,X/46,XY mosaicism followed by in vitro fertilization pregnancy

“…Nomura et al [15] reported that the proportion of peripheral blood with 46,XY cells in the phenotypic male patients was lower than 0.2%, while that was 50% in gonads. Wu et al [16] found that the proportion of 46,XY cells in phenotypic female patient could reach 60%. In our case, the proportion of 46,XY cells in peripheral blood was only 10%, whereas the proportion of XY cells in testis was 78%.…”