Lack of pathogenic mutations in six patients with MMPSI.

Sequencing of the KCNT1, PLCB1, SCN1A and TBC1D24 loci was performed in six children with typical features of malignant migrating partial seizures of infancy (MMPSI), to verify the presence of potential disease-causing mutations, including those already reported to be associated with the disease. Sanger sequencing failed to identify in these genes the previously reported pathogenic mutations in these patients, while a comprehensive mutational scanning analysis of these four loci by targeted re-sequencing led to detection of both intronic and exonic new variants. Based on the current knowledge, the sequence variants identified here do not allow to predict functional phenotypes that might explain, at least in part, MMPSI symptoms.