SCN1A and encephalopathy, progressive, early-onset, with brain edema and/or leukoencephalopathy: To test whether a PCDH19 deficiency might be implicated in some epileptic encephalopathies resembling Dravet syndrome, we sequenced the coding region of this gene in 73 SCN1A-negative probands (the remaining 40 patients of the initial series plus 33 additional patients, for a total of 45 females and 28 males).