In which inheritance pattern does aqueductal stenosis occur?

Aqueductal stenosis, a condition characterized by the narrowing of the cerebral aqueduct, often leads to obstructive hydrocephalus. This condition is primarily associated with X-linked recessive inheritance.

X-linked recessive disorders are caused by mutations on the X chromosome. Since males have one X and one Y chromosome, they are more severely affected by X-linked recessive conditions, as they lack a second X chromosome that might carry a normal allele. Females, having two X chromosomes, can be carriers of the mutation without expressing the condition, assuming one X carries the normal allele. In the case of aqueductal stenosis, mutations affecting genes linked to the development of the aqueduct have been identified on the X chromosome.

Thus, individuals affected by aqueductal stenosis typically exhibit clinical features that align with this inheritance pattern, notably among male individuals who display the phenotype while females may be carriers without symptoms. The understanding of this inheritance provides important implications in genetic counseling and risk assessment.