Endocrine Abstracts

Introduction: Isolated hypogonadotropic hypogonadism is a heterogeneous group of genetic abnormalities affecting the hypothalamic pituitary gonadal axis. The main mechanism consists of an impairment of the production or the action of gonadotropin releasing hormone (GnRH). While several mutations have been identified, the majority of cases remain without etiology. The objective of our study was to describe the clinical and biological profiles of these diseases.

Methods: This was a retrospective study that included patients followed in our department between 2009 and 2023 for idiopathic hypogonadotropic hypogonadism with normal pituitary imaging. Patients with Kallmann syndrome were not included.

Results: We included 15 patients in our study. Twelve patients were males and three were females with a male/female sex ratio (M/F) of 4. The mean age at the initial diagnosis was 26.5±14.5 years with extremes ranging from 14 to 57 years old. The chief complaint was different depending on gender. For males, delayed puberty was the most common (n=4). Three patients complained of gynecomastia, two of micropenis, one patient consulted for infertility and another for adrenal insufficiency. For females, reasons for consultation were primary amenorrhea (n=1), secondary amenorrhea (n=1) and adrenal insufficiency (n=1). All patients reported a history of irregular menses. Most patients did not have a family history of hypogonadism (n=13), cryptorchidism and infertility were reported in first-degree relatives in two patients. Only one patient had first-degree parental consanguinity. No patient had a congenital malformation. The mean serum testosterone level was 0.99±0.9 ng/ml for men and the mean serum estradiol level was 9 pg/ml for women. The mean (FSH/lH) ratio was 3.8±3.6. An associated pituitary deficiency was observed in six patients. Corticotropic deficiency was the most frequent (n=5). Six patients were married, three of them had offspring: one couple had a spontaneous pregnancy and two couples needed treatment with gonadotropins to have children.

Conclusion: Isolated hypogonadotropic hypogonadism is characterized by heterogeneous genetic, clinical and evolutive aspects. The identification of the mutations involved in its genesis is crucial to improve its management and prognosis.