KCNQ2 - Related Epilepsy: geno - phenotype relationship with tailorized anti seizures medication (ASM): Systematic review

: Autosomal dominant mutations of KCNQ2 gene cause two epileptic disorders: Benign Familial Infantile Epilepsy (BFIE) and Early Onset Epileptic Encephalopathy (EOEE). Identifying the best reported therapy for these patients is the aim of this systematic Methods: we searched on Pubmed using the search terms "KCNQ2" AND "therapy" and "KCNQ2" AND "treatment"; we found 304 papers, of these, 29 met our criteria. We selected the data of 194 patients. All 29 papers were retrospective studies. Results: 104 patients were classified as EOEE, 90 as BFIE. After starting the treatment, 95% of BFIE became seizure-free while only in 73% of those with EOEE the seizures stopped.. Phenobarbital and sodium channel blockers were the most used treatment in BFIE. Most of the EOEE patients needed polytherapy and in the great majority, their outcome was severely affected (77%). Missense mutations were discovered in 96% of EOEE patients; they were prevalent but with a lower percentage also in BFIE ones (50%), followed by large deletion (16%), truncating (16%), splice donor site (10%) and frameshift (7%). Conclusions: Phenobarbital or Carbamazepine are reported to be the most effectivedrugs for child who have "benign" course, instead polytherapy is often necessary in EOEE patients, even if did not improve their neurological outcome In EOEE patients, mutations were located most frequently in S4 and S6 Helix and this could be an important information for developing new specific drugs.