Male hypogonadotropic hypogonadism in various genetic disorders

Introduction and purpose: Male hypogonadism is diagnosed in patients with total testosterone under 9-12nmol/L (250-350ng/dl) in serum which is associated with numerous symptoms which can severely lower the quality of patients life. Due to the cause and associated levels of gonadotropins it can be divided to hypergonadotropic and hypogonadotropic hypogonadism. Hypogonadotropic hypogonadism occurs far less often, but it’s considered to remain underdiagnosed. The purpose of this study is to review most of the inborn diseases that involve hypogonadotropic hypogonadism as one of their components.Current state of knowledge: Patients with Kallmann syndrome constitute the majority of confirmed hypogonadotropic hypogonadism cases, however due to variable epidemiological data and differing diagnosing processes the exact incidence cannot be estimated – it ranges from 1 in 85 000, to 1 in 5000 males and about 3-4 times less often in women. Other conditions that can occur with hypogonadotropic hypogonadism are Isolated Gonadotropin-Releasing Hormone deficiency, Gonadotropin disorders, Prader-Willi Syndrome, some pleiotropic syndromes like CHARGE syndrome, Patau syndrome, Pfeiffer syndrome, Hartsfield syndrome, Waardenburg syndrome, Bardet-Biedl syndrome, or other syndromes. The evaluation and treatment of some of these conditions does not involve hypogonadism or other gonadal disorders due to short lifespan, which cause the underestimations in hypogonadism morbidity.Conclusions: Regardless of lower incidence of hypogonadotropic hypogonadism compared to hypergonadotropic type, endocrinologists should stay aware of its under-diagnosis and actively search for signs of low gonadotropic hormones and gonadotropin-releasing hormone levels in hypogonadal patients.