Clinical and PRRT2 gene variants analysis of three families with benign familial infantile epilepsy / 中华神经科杂志

ABSTRACT

Objective:To investigate the clinical and gene variant characteristics of benign familial infantile epilepsy in generations of three families.Methods:The clinical data of the three benign familial infantile epilepsy patients with PRRT2 gene variant who were diagnosed and their family members were collected from Children′s Hospital Affiliated to Zhengzhou University between 2018 and 2019. All coding exons from the patients and their parents were screened by targeted next-generation sequencing, and detected variants were verified by Sanger sequencing.Results:In all the patients, a cluster of seizures was observed before one year old,but interictal clinical conditions were normal. The electroencephalograms were all normal in interictal stage. The father of proband 1 presented with convulsion onset at the age of eight months and showed remission before one year old. The grandpa, mother and uncle of proband 2 also presented with convulsion onset in their babyhood of life and showed remission before one year old. The mother of proband 3 presented with convulsion onset in their babyhood of life and showed remission before three years old. Proband 1 carried heterozygous c.937G>C variant in the PRRT2 gene which is inherited from his father. Proband 2 carried c.1075_c.1076insC variant inherited from his mother. A deletion of PRRT2 gene exon 2 was detected in both of proband 3 and her mother. The three variants had not been reported in the Human Gene Mutation Database.Conclusions:Benign familial infantile epilepsy is a kind of inherited epilepsy characterized by early onset of seizure in babyhood with better prognosis, a cluster of focal seizures with or without secondary generalization, and cessation of seizure mostly before two or three years of age. The variants c.937G>C, c.1075_c.1076insC and the deletion of exon 2 in the PRRT2 gene have enriched the gene variant spectrum of benign familial infantile epilepsy.