We herein report 3 cases of Mowat-Wilson syndrome, characterized by distinct 
facial features, severe psychomotor retardation, and epilepsy, recurring in 3 
siblings from the same parents. The proband was a 15-month-old boy, the youngest 
of 3 children (2 elder sisters), who was referred to our hospital for the 
treatment of severe seizures. The clinical features and course of these 3 
siblings were compatible with those of previously reported Mowat-Wilson syndrome 
patients, and all siblings had the same E87X nonsense mutation in ZFHX1B, 
whereas their mother did not show the mutation. Because Mowat-Wilson syndrome 
has been caused by de novo mutation in ZFHX1B, germ-line mosaicism should be 
considered if recurrence in siblings is observed.