Kallmannszindróma

Kallmannszindróma is a genetic disorder characterized by the combination of hypogonadotropic hypogonadism and anosmia, or a reduced sense of smell. In individuals with Kallmann syndrome, the olfactory bulbs, the brain structures responsible for processing smell, are underdeveloped or absent. This deficiency in olfactory pathways is linked to a disruption in the migration of GnRH-producing neurons from the olfactory placode to their normal location in the hypothalamus. Gonadotropin-releasing hormone (GnRH) is crucial for the development and function of the reproductive system.

The primary clinical manifestations of Kallmann syndrome are delayed or absent puberty and infertility due to insufficient sex hormone production. In males, this can result in a small penis, undescended testes, and lack of secondary sexual characteristics such as deep voice and facial hair. In females, it can lead to the absence of menstruation and underdeveloped breasts. The severity of anosmia can vary, ranging from a complete inability to smell to a diminished sense of smell.

Kallmann syndrome is typically inherited in an X-linked recessive pattern, although autosomal dominant and autosomal recessive forms also exist. Several genes have been identified that are associated with the condition, including KAL1, FGFR1, PROKR2, and PROK2. These genes play roles in neuronal migration and development. Diagnosis is usually made based on clinical presentation and confirmed with hormonal tests that show low levels of gonadotropins (LH and FSH) and sex hormones, along with olfactory testing. Treatment involves hormone replacement therapy to induce puberty and maintain sexual function.