Abstract: Objective　To explore the clinic characteristics of epilepsy with mental retardation limited to females (EFMR) and the mutations of PCDH19 gene. Methods　The clinic feature, EEG, brain MRI, gene mutations detected by Sanger sequencing or targeted next generation sequencing and treatment were retrospectively analyzed. Results　The patient was a one year and eleven months old girl. Seizures onset was sensitive to heat, occurring in clusters and various forms. At the same time, the patient showed cognitive retardation and autism-like performance. A de novo PCDH19 gene mutation was found. Few spike waves were occurred in the EEG. The brain MRI was normal. The treatment of this disease’s epileptic attack was difficult. Conclusions　Onset in EFMR is characterized in clusters and sensitive to fever. Early epilepsy gene detection helps to evaluate prognosis of the disease and offers genetic counseling.

Key words: 　epilepsy and mental retardation limited to females;　protocadherin 19;　de novo mutation