Hidden Y Chromosome Mosaicism in 48 Egyptian Patients with Turner’s Syndrome

Abstract

Background. The presence of Y chromosome material in Turner's syndrome (TS) patients is a risk factor for the development of gonadoblastoma. Although conventional cytogenetic analysis is the definitive diagnosis of TS, low level Y chromosome mosaicism may be missed. Molecular analysis has demonstrated a higher proportion of mosaicism, but there is controversy regarding the prevalence of Y chromosome-derived material in those patients. Aim and Methods. This study was conducted to investigate the prevalence of hidden Y chromosome mosaicism in 48 TS Egyptian patients using polymerase chain reaction (PCR) for molecular DNA analysis of SRY gene and compare our results with those in the literature. Results. None of TS patients had a cytogenetically obvious Y chromosome; Y chromosome material was detected only at molecular analysis. SRY gene was found in 9 TS patients (18.75%) with the classical 45,X karyotype, whereas all other patients were SRY negative. Conclusion. Cytogenetically undetected Y chromosome mosaicism is common in TS patients; these data reinforce the need for adequate diagnosis of Y chromosome material in those patients. Molecular screening for Y chromosome-derived DNA should be routinely carried out in all TS patients.

Molecular Detection and Incidence of Y Chromosomal Material in Patients with Turner Syndrome

“…These tumors can be gonadoblastomas (GBs), which are composed of germ cells and stromal cells. Unfortunately, in 60% of GB cases, there is a potential to progress towards invasive germ cell tumors (mostly dysgerminoma and less frequently embryonic carcinoma, teratoma, yolk sac tumors, and choriocarcinoma) [Saenger, 1993;El-Eshmawy et al, 2013]. Approximately 95% of patients with GB show Y chromosomal material in genetic testing [de Marqui et al, 2016].…”