Amenorrea primaria por hipogonadismo hipogonadotropo normosómico

We describe the case of an adopted 17-year-old girl who consulted because of complete pubertal delay. No specific dysmorphic features were observed and olfaction was normal. The complete absence of pubertal development had severe psychological effects. Basal hormonal determinations confirmed severe hypoestrogenism, with serum gonadotropins within the normal range for the early follicular phase. Serum levels of other pituitary hormones were normal. A sellar magnetic resonance imaging (MRI) scan was normal. Both gonadotropins increased normally in response to gonadotropin-releasing hormone (GnRH) (100 μg, IV). Spontaneous gonadotropin secretion through a 12-h nocturnal period showed minimal luteinizing hormone (LH) pulsatility with nocturnal increase and less follicle-stimulating hormone (FSH) pulsatility without nocturnal increment. A diagnosis of normosomic hypogonadotropic hypogonadism was made. The patient was treated with progressive doses of conjugated estrogens, with subsequent addition of progesterone in a cyclic regimen. Finally, oral contraception was prescribed. At 26 years of age, she desired fertility and was clinically reevaluated. Partial hypogonadotropic hypogonadism was confirmed, with similar patterns of spontaneous gonadotropin secretion and GnRH response. We discuss the clinical characteristics of this entity, focusing mainly on the cause of normosomic hypogonadotropic hypogonadism, in light of new information about the molecular bases of these disorders. The treatment of hypogonadotropic hypogonadism is also discussed.