ENOrphanet Journal of Rare Diseases | The Danish Turner Syndrome Ovarian Tissue Cryopreservation Study: A Prospective Cohort Study Protocol
Date: April 05, 2025
Classification: Frontiers
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This article introduces the design and preliminary follow-up protocol of the Danish Turner Syndrome ovarian tissue cryopreservation study, aiming to evaluate the long-term reproductive outcomes of ovarian tissue cryopreservation (OTC) in girls with Turner syndrome. The study integrates clinical assessment with molecular analysis to explore predictive factors for ovarian function preservation, offering scientific support for future fertility interventions.
Literature Overview
The article titled The Danish Turner Syndrome Cryopreservation Study: PROTOCOL for a prospective cohort study on reproductive outcomes after ovarian tissue cryopreservation in girls with Turner syndrome, published in Orphanet Journal of Rare Diseases, reviews the mechanisms of ovarian function decline in Turner syndrome (TS) patients and its impact on fertility. It highlights that TS women often experience early ovarian failure due to X chromosome deletion or abnormalities, leading to infertility. OTC, an experimental fertility preservation method, has not been widely applied or validated in TS patients. The article presents the design of a nationwide Danish prospective cohort study aimed at systematically assessing the long-term reproductive outcomes of OTC in TS girls, while exploring early biomarkers and molecular mechanisms of premature ovarian insufficiency (POI).
Background Knowledge
Turner syndrome is a rare genetic disorder caused by complete or partial loss of the X chromosome, primarily affecting the development of the female reproductive system, especially ovarian function. Most TS women experience ovarian failure before puberty, with only a few achieving spontaneous development or fertility. Currently, no effective treatment exists to reverse ovarian function loss, making OTC a potential fertility preservation strategy. While OTC has been proven effective in cancer patients, it remains experimental in TS patients, with only a few transplant cases reported and no live births documented. The study focuses on the molecular mechanisms of ovarian function decline in TS women, particularly the expression and methylation changes of escape genes on the X chromosome, such as KDM6A, USP9X, and ZFX. Additionally, the study evaluates the impact of OTC on bone density, body composition, quality of life, and future pregnancy risks. High-quality data on long-term reproductive outcomes after OTC in TS patients are lacking, and this study aims to fill this gap, providing evidence for clinical decision-making.
Study Design and Methods
This nationwide prospective cohort study recruits TS girls aged 2–17 years. Ovarian function is assessed using hormone levels (AMH, Inhibin B, FSH, LH, E2), and imaging techniques such as transabdominal ultrasound (TAUS) or MRI. If ovarian reserve is deemed sufficient, unilateral oophorectomy is performed via laparoscopy, followed by ovarian tissue cryopreservation in the lab. Some tissues are used for histological and molecular analysis, including DNA methylation, gene expression, and proteomics. The study also includes non-standard assessments such as bone density (DXA, HRpQCT), activity monitoring, and quality of life surveys (WHO-5 and SWLS scales). Follow-up will assess pregnancy outcomes, hormone recovery, and ovarian function changes after autologous transplantation.
Key Findings and Perspectives
Significance and Future Directions
This study will provide the first systematic evaluation of long-term reproductive outcomes after OTC in TS patients, offering longitudinal data on ovarian function decline. The results will help optimize selection criteria for OTC and provide scientific support for fertility counseling in TS. Future work will integrate molecular mechanism analysis to identify more reliable ovarian function biomarkers, promoting personalized fertility preservation strategies.
Conclusion
The Danish Turner Syndrome Ovarian Tissue Cryopreservation Study is an important prospective cohort study aimed at systematically evaluating the feasibility and long-term reproductive outcomes of OTC in TS girls. It not only focuses on the clinical implementation of OTC but also explores the molecular mechanisms of ovarian function decline in TS, particularly methylation and expression changes of X-chromosomal escape genes. By integrating hormonal assessments, imaging, and molecular analysis, the study aims to build a more accurate predictive model of ovarian function. As autologous transplantation after OTC in TS patients remains experimental and no live births have been reported, this study will provide critical data for clinical decision-making, helping physicians and families make more informed choices about fertility preservation. Additionally, the study will assess the potential impact of OTC on puberty, bone health, and quality of life, offering scientific support for ethical and risk assessments in TS fertility interventions. The study is expected to last until 2050 and may lay the foundation for future TS fertility treatments.
