The PAG program has developed a protocol for ovarian tissue cryopreservation for prepubertal children with Turner syndrome, classic galactosemia and adolescents with recent primary ovarian insufficiency (POI). In this protocol one ovary will be removed, 80% of the tissue will be stored for future use by the patient and 20% will be saved for research with the following aims:

• Clinical phenotyping and histologic evaluation: We hope to determine through deep clinical phenotyping and histologic evaluation whether patients with Turner syndrome, classic galactosemia, and adolescents with recent premature ovarian insufficiency (POI), have ovaries containing viable follicles and whether these correlate with currently known (and any identified in the future) ovarian reserve markers.
• Single-Nucleus RNA Sequencing: The critical mechanisms of follicle activation and atresia are incompletely understood. Single-nucleus RNA (sn-RNA seq) sequencing provides a way to obtain transcriptome profiles and can be performed on frozen tissue. Frozen ovarian tissue samples from OTC will be studied and compared to that of age-matched cadaveric organ donors. Through sequencing of ovarian tissue from children with Turner syndrome and classic galactosemia, we hope to begin to elucidate possible mechanisms of follicle loss in these conditions

For more information regarding the study, please visit https://clinicalstudies.info.nih.gov/protocoldetails.aspx?id=000106-CH&&query= and https://clinicaltrials.gov/ct2/show/NCT04948658