Congenital Hydrocephalus Inheritance: Genetic Risk and Genetic Counseling

Hydrocephalus = excess CSF in ventricles. Etiology determines heritability.

• Congenital (present at birth): May be genetic (e.g., L1CAM X-linked hydrocephalus, MPDZ, CCDC88C), part of a syndrome (Dandy-Walker, aqueductal stenosis), or multifactorial.
• Acquired (postnatal): Hemorrhage (IVH), infection (meningitis), tumor, trauma – not inherited.

Recurrence Risk

• Isolated aqueductal stenosis: ~2% (multifactorial).
• X-linked L1CAM: 50% males affected, 50% females carriers.
• Autosomal recessive: 25% recurrence.

Action

Referral to genetic counselor or neurogenetics clinic. Prenatal ultrasound (ventriculomegaly screening), fetal MRI, and targeted gene panel/exome sequencing if indicated.