Endocrine Abstracts

Background: Primary Ovarian Insufficiency (POI) is defined as the loss of ovarian function before age 40. It is characterized by menstrual disturbance with raised gonadotropins (>25 UI/l). It can manifest as primary amenorrhea (PA) or secondary amenorrhea (SA). The causes of POI include chromosomal and genetic defects, autoimmune processes, chemotherapy, radiation, infections, and surgery. However, the etiology remains unidentified in 80% of cases referred to as idiopathic POI.

Material and Methods: We report the clinical and cytogenetic study of 90 patients diagnosed with POI, collected at the Department of Congenital and Hereditary Diseases of Charles Nicolle Hospital in Tunis (Tunisia) over a period of 7 years from January 2016 to December 2022. R-banded chromosome analysis on cultured peripheral blood lymphocytes was performed in all patients.

Results: The 90 patients were referred for PA (36/90), SA (19/90), POI (26/90), and spaniomenorrhea (9/90). Their average ages were 22.9 years (14-39 years), 22.9 years (17-36 years), 32.8 years (18-40 years), and 23.6 years (14-40 years), respectively. Hormonal assessment data reported in only 46 medical files (46/90) showed high levels of FSH (>25 UI/l) in the 46 patients. Pelvic imaging was performed for 33 patients (26 ultrasounds and 7 MRIs) and revealed anomalies in 17 patients consisting in the absence of uterus and/or vagina (4/17), non-visualized ovaries (10/17), or hypoplastic ovaries (3/17). Karyotype showed anomalies in 12 patients (13.3 %): a Turner syndrome in 8/12 patients due to monosomy X in 5/8 patients (mosaic 3/5, homogenous 2/5), mosaic Xq isochromosome in 2/8 patients, and a mosaic ring X chromosome in 1/8 patient, all of them having PA, a supernumerary marker chromosome in one patient with SA (1/12), a balanced translocation 46,X,t(X;17)(q21.3;q22) in one patient with SA (1/12) and 46,XY Karyotype in two patients with female phenotype, gonadal dysgenesis and PA(2/12).

Conclusion: These results are consistent with those reported in the literature. Indeed, in our study, chromosomal anomalies were responsible for 13.3% of POI cases vs 10-13% in the literature, the majority of which are X chromosome abnormalities. According to this high rate of chromosomal abnormalities, the karyotype must be performed for all patients with non-iatrogenic POI as recommended by the European Society of Human Reproduction and Embryology (ESHRE,2015).