Protocadherin 19 belongs to the non-clustered delta protocadherin subgroup within the cadherin superfamily, which is primarily expressed in the central nervous system in early brain development.[1] The causative gene PCDH19, which encodes protocadherin 19, is located on chromosome Xq22.1, a region subjected to X-chromosome inactivation and plays an important role in neuronal connections and signal transduction.[5] PCDH19 genomic variants, generally involving the exon1, are correlated with the developmental and epileptic encephalopathy. The gene discussed is CDH17; the disease is Epileptic encephalopathy.