What is the primary genetic inheritance pattern for Kallmann Syndrome?

The primary genetic inheritance pattern for Kallmann Syndrome is X-linked recessive. This condition is associated with the disruption of normal migration of gonadotropin-releasing hormone (GnRH) neurons from the olfactory bulb to the hypothalamus during embryonic development. The most common form of Kallmann Syndrome is caused by mutations in the KAL1 gene, which is located on the X chromosome, leading to its classification as X-linked.

In X-linked recessive inheritance, males who inherit a single mutated copy of the gene on their only X chromosome will express the condition, while females, having two X chromosomes, typically need to inherit two copies of the mutated gene to express the disorder. This pattern results in a higher prevalence of Kallmann Syndrome in males compared to females.

While Kallmann Syndrome can also have rare forms that are inherited in different ways, such as autosomal dominant or autosomal recessive, the majority of cases are classified through the X-linked pattern. Understanding these inheritance patterns is crucial for genetic counseling, diagnosis, and risk assessment for affected families.