Specific Types & Syndromes
X-linked hydrocephalus (L1 syndrome)
X-linked hydrocephalus is an inherited form, affecting mainly boys, caused by changes in the L1CAM gene.
In short: X-linked hydrocephalus (L1 syndrome)
- It is an inherited form affecting mainly boys.
- It is caused by changes in the L1CAM gene.
- It often involves aqueductal stenosis.
- Genetic counseling is important for affected families.
What it is
X-linked hydrocephalus is an inherited form of hydrocephalus caused by changes (variants) in the L1CAM gene, located on the X chromosome. Because of its X-linked inheritance, it affects mainly boys.
Understanding X-linked hydrocephalus (L1 syndrome)
Changes in the L1CAM gene can disrupt brain development, often producing aqueductal stenosis (narrowing of the cerebral aqueduct) and other features. It is part of a spectrum sometimes called L1 syndrome, which can include additional findings such as adducted thumbs and other neurological features. X-linked hydrocephalus accounts for a small proportion of all hydrocephalus but a notable share of inherited hydrocephalus in boys. Because it is genetic, genetic counseling and testing are important for affected families to understand the inheritance pattern and recurrence risk in future pregnancies. The hydrocephalus is managed with CSF diversion as needed.
Why it matters
Understanding X-linked hydrocephalus helps families see that some hydrocephalus is inherited, why it affects mainly boys, and why genetic counseling is valuable for understanding recurrence risk and the broader condition.
Common questions
What causes X-linked hydrocephalus?
Changes in the L1CAM gene.
Who does it mainly affect?
Boys, due to its X-linked inheritance.
Why is genetic counseling important?
To understand inheritance and recurrence risk.
Bottom line
X-linked hydrocephalus is an inherited form affecting mainly boys, caused by L1CAM gene changes, often with aqueductal stenosis.
Browse all 265 Hydrocephalus definitions
Read the Hydrocephalus patient guides
Not sure which page you need? Put words to it with the symptom navigator