[Analysis of parental origin of de novo SCN1A mutations in Dravet syndrome].
To analyze the parental origin of de novo SCN1A mutations in 22 patients with Dravet syndrome (DS). Clinical data and peripheral blood DNA of the patients and their parents were collected. SCN1A gene mutation was screened by polymerase chain reaction (PCR) and Sanger sequencing. For de novo mutations, allele-specific-PCR (AS-PCR) was used to determine their parental origins. Should the mutations be of paternal origin, semen specimen for their fathers was analyzed using PCR and Sanger sequencing for SCN1A gene mutations. The parental origins of 22 de novo mutations were successfully determined by AS-PCR. Nineteen (86.4%) of the mutations had a paternal origin and 3 (13.6%) had a maternal origin. For those with a paternal origin, semen samples from 9 fathers were analyzed, but no mutation was found. The majority of de novo SCN1A mutations were of paternal origin. The same mutation was not found in semen samples from the fathers, for which deep sequencing may be necessary.