PCDH19 and Global developmental delay: Importantly, epileptic encephalopathy early infantile 65 (EIEE65, caused by dysfunctional CYFIP2, a protein belonging to WRC) is characterized by early onset of intractable seizures and severe psychomotor developmental delay (Nakashima et al., 2018), which are clinical features in common with PCDH19-CE (also known as epileptic encephalopathy, early infantile 9, EIEE9).