PCDH19 (Protocadherin 19)-related childhood-onset epilepsy syndrome, recently named epileptic encephalopathy, early infantile, type 9, developmental and epileptic encephalopathy-9 (DEE9) or Juberg-Hellmann syndrome (OMIM#300088), is a female-restricted, X-linked disorder with an extraordinary male-sparing inheritance pattern (affects heterozygous females and mosaic males only; hemizygous males are unaffected) and an estimated 4.85 per 100,000 live born females [1,2]. Here, PCDH19 is linked to childhood-onset epilepsy syndrome.