Hypogonadotropic hypogonadism due to pathogenic variants in the POLR3B gene

Congenital hypogonadotropic hypogonadism (СНH) is a group of diseases caused by impaired synthesis or secretion of gonadotropin-releasing hormone (GnRH) and gonadotropin hormones. At present, more than twenty genes involved in the development of СНН have been described. In the structure of HGH, the most common forms of the disease are caused by pathogenic variants in genes involved in the ontogenesis, migration and survival of GnRH neurons, whereas pathology of genes involved in the action/transmission of GnRH signals in normally developed GnRH neurons is less common. This article describes a rare variant of СНН as a result of pathogenic variants in the POLR3B gene, occurring in 1.1% of cases of СНН, which is a component of hypomyelinating leukodystrophy 4H and includes hypomyelination, CHН, hypodontia. Identification of the genetic nature of the disease in this patient made it possible not only to establish the cause of CНН, but also to diagnose comorbid conditions.