Kallmann syndrome is associated with which type of developmental abnormality?

Kallmann syndrome is primarily associated with a failure of neuron migration during development. This disorder leads to hypogonadotropic hypogonadism, which is characterized by a deficiency in the production of gonadotropin-releasing hormone (GnRH). In typical embryonic development, GnRH-producing neurons originate in the olfactory placode and migrate to the hypothalamus; however, in individuals with Kallmann syndrome, this migration process is disrupted. The failure of these neurons to reach their proper location results in the characteristic endocrine issues related to inadequate gonadotropic stimulation of the gonads.

The olfactory system is also affected, contributing to the anosmia or hyposmia frequently observed in affected individuals. Understanding this migration failure is crucial in recognizing the underlying pathophysiology of Kallmann syndrome and differentiating it from other types of developmental abnormalities that involve distinct mechanisms.