Kallmann syndrome: Diagnostics and management

Abstract

Kallmann syndrome is a genetic disorder characterized by delayed or absence of puberty and a reduced or absent sense of smell (anosmia). Kallmann syndrome is a form of hypogonadotropic hypogonadism due to lack of the production of sex hormones which is associated with development of secondary sexual characteristics. Kallmann Syndrome is a genetically heterogeneous disorder, characterized by the combination of hypogonadotropic hypogonadism (a deficiency in sex hormone production) and anosmia. Germline mutations in KAL1 gene causes deficiency in GnRH hormone followed by low level of circulating gonadotropin and testosterone which finally leads to the failure of puberty (development of secondary sexual characters). Kallmann Syndrome can be inherited in several manners including X-linked recessive (e.g., mutations within KAL1) and autosomal dominant and recessive forms. Germline mutation in KAL1 gene was identified among 8% of patients with Kallmann Syndrome. A review of the recent literature done reveals numerous clinical manifestations in Kallmann Syndrome patients with the KAL1 mutation, including microgenitalia, impotence, reduced libido, infertility, unilateral renal agenesis, and synkinesia. Genetic molecular diagnostics through prenatal diagnosis and preimplantation genetic testing are most significant way to reduce the risk of Kallmann syndrome in next generation. Complication associated with Kallmann syndrome can be prevented by early diagnosis, diet supplementation and medical therapy. Goal of therapeutic intervention is to the development of secondary sexual characteristics, build and sustain bone density as well as muscle mass and restore fertility. This review aims to explore the genetic diagnosis and management strategies for Kallmann Syndrome, particularly focusing on KAL1 gene mutations.