Infantile and childhood epileptic encephalopathies encompass a wide, heterogeneous group of epilepsies characterized by various types of seizures, frequent epileptiform activity on EEG, and developmental delay or regression. Genetic causes have   been  described in several of the epileptic encephalopathies, and many previously unknown genes have been identified. WW domain-containing oxidoreductase (WWOX) has been recently implicated in autosomal recessive spinocerebellar ataxia type 12 (SCAR12) and severe early-onset epileptic encephalopathy. We identified a homozygous WWOX mutation, p.Leu239Arg, in five patients (3 boys, 2 girls) from three different families with psychomotor developmental delay, acquired microcephaly, and epileptic seizures. WWOX related epileptic encephalopathy is a rare condition but it must  be considered in cases having early epileptic spasms and parental consanguinity. The increasing use of new generation genetic analyses in the diagnosis of IEE will result in a broader range of newly identified genes and phenotypes associated with existing genotypes. The use of diagnostic genetic panels might be useful for  preventing diagnostic delay in those patients and giving more appropriate genetic counseling of their families.