Unravelling the Impact of an Additional Sex Chromosome in an Adult Female.

Women with Triple X syndrome (TXS) appear to be at increased risk for decreased ovarian reserve; however, available data are limited. We present an asyndromic adult female with features of recurrent pregnancy loss and decreased ovarian reserve detected with mosaic Triple X syndrome (TXS). The patient was initially evaluated by a low-cost peripheral blood (PB) conventional karyotyping using standard cytogenetic protocols. Interphase fluorescence in situ hybridisation was performed to confirm the diagnosis. Chromosomal microarray, which is a more expensive test, substantiated the presence of additional X chromosomes but failed to detect the presence of low level of mosaicism. Our case study emphasised the recommendation of performing a strategy-based cost-effective cytogenetic evaluation of all cases of decreased ovarian reserve or low anti-Müllerian hormone levels in a resource-constrained setting. It also highlighted the need for additional research to understand the natural history of ovarian function in TXS affected women throughout their lifespans.

Mosaic Turner Variant Adult Female Presenting with XO/XY Karyotype.

Turner syndrome (TS) is the most frequently detected chromosomal abnormality in females caused by the partial or complete absence of second X chromosome. Due to varied phenotypical presentation, the diagnosis of TS can create a spectrum of clinical concerns related to morbidity and mortality. At least 10% of Turner females exhibit the presence of Y chromosome or Y-derived sequences. Patients with 45,X/46,XY mosaicism may have a phenotypic variation of the external genitalia and exhibit features ranging from normal male to ambiguous to female genitalia with features of TS. Turner mosaic variants with Y chromosome components have increased risk for gonadoblastoma. Although the risk is not exactly quantifiable, according to the 2016 Cincinnati International TS Meeting Clinical Practice guidelines, bilateral prophylactic gonadectomy is mandatory if Y chromosomal component is identified in mosaic Turner. We describe a rare case of an adult female patient detected as mosaic Turner variant with the presence of Y chromosome and reconfirmed by an aneuploidy FISH probe.