X-linked hydrocephalus with stenosis of the aqueduct of Sylvius

X-linked hydrocephalus with stenosis of the aqueduct of Sylvius is a severe form of L1 syndrome that usually appears before birth. In this condition, changes in the L1CAM gene lead to a narrowing of the channel (aqueduct of Sylvius) that allows fluid to flow in the brain, which can cause a buildup of fluid known as hydrocephalus. People with this condition may show signs of increased pressure in the skull (intracranial hypertension), which can affect brain function. Additional features can include adducted thumbs (where the thumbs turn inward), muscle stiffness (spasticity), and severe intellectual deficits. Overall, this condition is considered to be at the severe end of the spectrum with a generally poor prognosis.

Common symptoms include severe hydrocephalus, typically identified before birth, signs of increased pressure in the brain, inward-turning thumbs, spasticity (stiff muscles), and significant intellectual challenges.

This disorder is caused by changes (mutations) in the L1CAM gene. These genetic changes disrupt normal brain development, especially the flow of fluid in the brain, leading to the severe features seen in the condition.

Information about treatment is currently limited for this condition.

The condition is associated with a poor prognosis. Many people with this form of L1 syndrome have severe challenges and outcomes, especially given the prenatal onset and the significant effects on brain development.

Information about research is currently limited for this condition.