SAT-010 Non-Classic POR Deficiency as a Cause of Menstrual Disorders & Infertility

P450 oxidoreductase deficiency (PORD) is an autosomal recessive disease caused by bi-allelic mutations of the POR gene. It is responsible for decreased activity of several P450 enzymes including CYP21A2, CYP17A1 and CYP19A1 that are involved in adrenal and/or gonadal steroidogenesis. PORD is typically diagnosed in neonates and children with ambiguous genitalia and/or skeletal abnormalities. Adult-onset PORD has been very seldom reported and little is known about the optimal way to investigate and treat such patients. In this series, we report five women aged 19-38 years, who were referred for unexplained oligo-/amenorrhea and/or infertility. Genetic testing excluded 21-hydroxylase deficiency (21OH-D), initially suspected due to increased 17-hydroxyprogesterone (17-OHP) levels. Extensive phenotyping, steroid profile by mass spectrometry, pelvic imaging and next-generation sequencing of 84 genes involved in gonadal and adrenal disorders were performed in all patients. In Vitro Fertilization (IVF) followed by frozen embryo transfer under glucocorticoid suppression therapy was performed in two patients. All patients had oligomenorrhea or amenorrhea. None had hyperandrogenism. Low-normal serum estradiol (E2) and testosterone levels contrasted with chronically increased serum progesterone (P) and 17-OHP levels, which further increased after ACTH administration. Despite excessive P, 17OH-P and 21-deoxycortisol rises after ACTH stimulation suggesting non-classic 21-hydroxylase deficiency, CYP21A2 sequencing did not support this hypothesis. Basal serum cortisol levels were low to normal, with inadequate response to ACTH in some women, suggesting partial adrenal insufficiency. Pelvic imaging revealed bilateral ovarian macrocysts in all women. All patients were found to harbor rare bi-allelic POR mutations classified as pathogenic according to American College of Medical Genetics standards. IVF was performed in two women after retrieval of a normal oocyte number despite very low E2 levels during controlled ovarian hyperstimulation. Frozen embryo transfer under glucorticoid suppression therapy led to successful pregnancies. These observations suggest that diagnosis of PORD must be considered in infertile women with chronically elevated P and 17OH-P levels and ovarian macrocysts. Differentiation of this entity from non-classic 21-hydroxylase deficiency is important, as the multiple enzyme deficiency requires a specific management. Successful fertility induction is possible by IVF, providing that P levels be sufficiently suppressed by glucocorticoid therapy prior to implantation.