Improvement on BAF53B Mutation Caused Developmental and Epileptic Encephalopathy with a Ketogenic Diet

Purpose: Genetic mutation is the leading cause of Developmental and Epileptic Encephalopathy (DEE, OMIM 308350), a spectrum of disorders characterized by severe epilepsy and usually begins in infancy, accompanied with psychomotor development arrest and hypsarrhythmiaon electroencephalogram (EEG).Up till now, mutations of 101 genes were confirmed as the cause of DEE, and were categorized accordingly into 101 different sub-types (DEE1-101). Here, we report a case of DEE76 with a tortuous path to genetic diagnosis and an illuminating treatment of ketogenic diet (KD). Methods: Through high throughput sequencing, we identified a DEE76 case caused by biallelic BAF53B mutation inherited in an autosomal recessive manner, and report the pathogenic variants NM_016188.4:c.892C>T (p.Arg298*) and NM_016188.4:c.991_996delinsAA (p.Gly331Asnfs*44) for the first time. Results: The proband commenced seizures on day five after birth and rapidly deteriorated during development. After a series of therapeutic exploration, ketogenic diet turned out to be the most hopeful treatment available. Conclusion: ultra-rare gene therapy KD, seizures