SCN1B and SCN2B gene variants analysis in dravet syndrome patients: Analysis of 22 cases.

Previous research identified SCN1B variants in some cases of Dravet syndrome (DS). We investigated whether SCN1B and SCN2B variants are commonly happened in DS patients without SCN1A variants. A total of 22 DS patients without SCN1A variants and 100 healthy controls were enrolled in this genetic study. DNA from DS patients was sequenced by Sanger method in whole exons of SCN1B and SCN2B genes. We identified two exon variants (c.351C>T, p.G117G and c.467C>T, p.T156M), which were present both in 1000 egenomes database and in healthy controls with a frequency of 0.54% and 4%, 0.06% and 0%, respectively. Additionally, eight intron or 3 prime UTR variants showing benign clinical significance have also been identified. Our results suggest that variants of SCN1B and SCN2B may not be common causes of DS according to our data. Further large sample-size cohort studies are needed to confirm our conclusion.