L1CAM and X-linked intellectual disability - Dandy-Walker malformation - basal ganglia disease - Seizures: Second, a number of single-gene disorders have been associated with ventriculomegaly, such as L1 cell adhesion molecule (L1CAM)-associated hydrocephalus, Pettigrew syndrome, Walker–Warburg syndrome, Meckel syndrome, Joubert syndrome, etc.30, 31.