OBJECTIVE To report a case of a young girl initially diagnosed with exclusively 45,X Turner syndrome (TS), but with a cryptic mosaicism in the ovary. DESIGN Case report. SETTING Radboud University Medical Center in the Netherlands. PATIENT(S) A 14-year-old girl with TS showing an exclusively 45,X cell line in lymphocytes, buccal cells, and urine cells in the presence of ovarian follicles. INTERVENTION(S) Laparoscopic unilateral oophorectomy was performed to obtain ovarian cortex tissue for fertility preservation purposes. One cortex fragment was used to determine the number of follicles by serial sectioning and staining, to perform fluorescence in situ hybridization (FISH) analysis and an in vitro growth (IVG) assay. MAIN OUTCOME MEASURE(S) FISH analysis of ovarian cells and the capacity of unilaminar follicles to develop to secondary follicles. RESULT(S) FISH analysis revealed that most oocytes had a normal tetraploid X chromosomal content, the stromal cell compartment had both 45,X and 47,XXX cell lines, and all follicular granulosa cells had a 45,X karyotype. IVG assay showed that unilaminar follicles were capable of maturing to secondary follicles, but that the granulosa layers and membrana granulosa were distorted. CONCLUSION(S) We report a case where follicles were found in a girl with monosomic TS, in the presence of a cryptic mosaicism. Karyotyping of extraovarian cells was not predictive of the karyotype of ovarian cells in the same patient. Despite the presence of normal oocytes, our observation that all analyzed follicles contained exclusively 45,X granulosa cells embedded in mosaic 45,X/47,XXX stromal tissue may have functional consequences for follicular development. CLINICAL TRIAL REGISTRATION NUMBER NCT03381300.

中文翻译：

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为什么有些 45,X Turner 综合征患者可以生育？一个患有经典 45,X Turner 综合征和卵巢内隐匿嵌合体的年轻女孩

目的报告一例最初诊断为 45,X 特纳综合征 (TS) 的年轻女孩，但在卵巢中有隐匿性嵌合体。设计案例报告。在荷兰设立 Radboud 大学医学中心。患者 一名患有 TS 的 14 岁女孩，在有卵泡的情况下，淋巴细胞、颊细胞和尿细胞中仅显示 45,X 细胞系。干预措施 进行腹腔镜单侧卵巢切除术以获得卵巢皮质组织以保留生育能力。一个皮质片段用于通过连续切片和染色确定卵泡数量，以进行荧光原位杂交 (FISH) 分析和体外生长 (IVG) 分析。主要结果测量（S） 卵巢细胞的 FISH 分析和单层卵泡发育为次级卵泡的能力。结果 FISH 分析显示，大多数卵母细胞具有正常的四倍体 X 染色体含量，基质细胞区室具有 45,X 和 47,XXX 细胞系，并且所有滤泡颗粒细胞具有 45,X 核型。IVG检测显示单层卵泡能够成熟为次级卵泡，但颗粒层和膜颗粒变形。结论（S） 我们报告了一个病例，在一个患有单体性 TS 的女孩身上发现了卵泡，存在隐匿性嵌合体。卵巢外细胞的核型分析不能预测同一患者卵巢细胞的核型。尽管存在正常卵母细胞，但我们观察到所有分析的卵泡仅包含嵌入镶嵌 45,X/47,XXX 基质组织中的 45,X 颗粒细胞，这可能对卵泡发育具有功能影响。