[Genetics Analysis of patients with Dravet syndrome due to mosaicism variation of paternal SCN1A gene].

Genetic analysis was performed on a family of fraternal twins affected with Dravet syndrome by genetic tests whose parents were normal. To further analyze the cause of the disease, the fraternal twins were subjected to whole exome sequencing (WES), and the family was verified by Sanger sequencing, with the father semen and peripheral blood DNA were further analysed by target sequencing. The WES test identified a heterozygous c.5348C>T (p.Ala1783Val) variant of the SCN1A gene in the fraternal twins, which was predicted to be pathogenic and was detected in the father peripheral blood and semen, but not in the mother. So the mosaicism mutation of paternal SCN1A gene might be the genetic cause of Dravet syndrome in offspring.