Spontaneous ovarian hyperstimulation syndrome with a previously undescribed gene mutation of the follicle-stimulating hormone receptor gene: a case report

Objective: To present a case of a patient with recurrent spontaneous ovarian hyperstimulation syndrome (sOHSS) and a previously undescribed mutation of the follicle-stimulating hormone receptor (FSHR). Design: Case report. Subjects: A 23-year-old pregnant woman (gravida II) with recurrent spontaneous ovarian hyperstimulation during 2 consecutive singleton pregnancies. Exposure: Spontaneous conception in the presence of a heterozygous FSHR gene mutation. Main Outcome Measures: Clinical course of sOHSS, hormonal profile, sonographic findings, molecular genetic results, and maternal and fetal outcomes. Results: The patient presented at 12 weeks' gestation with massively enlarged bilateral multicystic ovaries (‟kissing ovaries") and mild ascites, without pleural effusion. Molecular genetic analysis revealed a previously unreported heterozygous FSHR mutation (c.1379T>A, p.Leu460Gln) in the transmembrane domain, classified as likely pathogenic according to American College of Medical Genetics and Genomics criteria. Conservative management resulted in gradual regression of ovarian size from the second trimester onward. The pregnancy was complicated by fetal growth restriction with normal uteroplacental and fetal perfusion parameters. Delivery by elective cesarean section at 38+0 weeks resulted in a healthy neonate. Conclusion: The discovery of a novel FSHR gene mutation, which is likely associated with sOHSS in this case, suggests that genetic factors may influence the development of this rare condition. It underlines the importance of considering genetic testing in managing and diagnosing sOHSS, potentially guiding more personalized and effective treatment strategies for affected women.