Li Li, Zhu Dandan
Department of Pediatrics, Luzhou Women and Children's Health Care Hospital, Luzhou, Sichuan 646000, China.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi. 2021 Feb 10;38(2):158-161. doi: 10.3760/cma.j.cn511374-20200120-00041.
To analyze the clinical features and genetic variants in two patients with Dravet syndrome (DS).
Peripheral blood samples of the children and their parents were collected for the extraction of genomic DNA and high-throughput sequencing. Suspected variants were confirmed by Sanger sequencing.
By high-throughput sequencing, the two children were found to respectively harbor a c.2135delC frameshifting variant in exon 12 and a c.1522G>T nonsense variant in exon 10 of the SCN1A gene. Both variants were predicted to be pathogenic by bioinformatic analysis. Based on the American College of Medical Genetics and Genomics standards and guidelines, the c.2135delC and c.1522G>A variants of the SCN1A gene were predicted to be pathogenic (PVS1+ PS2+ PM2+ PP3).
The variants of the SCN1A gene probably underlay the DS in the patients. Above finding has enriched the variant spectrum and enabled genetic counseling for their families.
分析2例Dravet综合征（DS）患者的临床特征及基因变异情况。
采集患儿及其父母的外周血样本，提取基因组DNA并进行高通量测序。通过Sanger测序确认可疑变异。
通过高通量测序，发现两名患儿分别在SCN1A基因的第12外显子存在一个c.2135delC移码变异，在第10外显子存在一个c.1522G>T无义变异。经生物信息学分析，这两个变异均被预测为致病性变异。根据美国医学遗传学与基因组学学会的标准和指南，SCN1A基因的c.2135delC和c.1522G>A变异被预测为致病性变异（PVS1+ PS2+ PM2+ PP3）。
SCN1A基因变异可能是这两名患者患DS的病因。上述发现丰富了变异谱，并为其家庭提供了遗传咨询。
