title: Characteristics of patients with benign partial epilepsy in infancy without PRRT2 mutations.
abstract: Mutations in the proline-rich transmembrane protein 2 gene (PRRT2) are known to cause clinical symptoms of paroxysmal kinesigenic dyskinesia (PKD), benign partial epilepsy in infancy (BPEI), and infantile convulsions with choreoathetosis (ICCA) syndrome; however, not all patients with BPEI have PRRT2 mutations, and the genetic backgrounds for such patients are still unknown. To characterize BPEI patients without PRRT2 mutations, we analyzed unrelated 63 patients with BPEI. Sanger sequencing identified PRRT2 mutations in 33 probands (52%). The most common insertion, c.649dup, was identified in 28 probands. Two novel truncation mutations, c.232dup and c.503_504del were identified independently. 16p11.2 microdeletion was not detected in patients without PRRT2 mutations. PRRT2 mutation detection rates were 21/31 (68%) and 12/32 (38%) in probands who were positive or negative for family history, respectively, indicating a significant difference between the two groups. In this study, 20 probands with BPEI were negative for family history of BPEI and negative for PRRT2 mutation. BPEI in these probands may be due to complex genetic predispositions. Because the possibility remains that a second gene contributes to BPEI, further studies are necessary in patients with BPEI but no PRRT2 mutation, especially in Asian people.
authors.affiliation: Department of Oral and Maxillofacial Surgery, School of Medicine, Tokyo Women's Medical University, Tokyo, Japan; Tokyo Women's Medical University Institute for Integrated Medical Sciences, Tokyo, Japan. Electronic address: sangu.noriko@twmu.ac.jp.
authors.forename: Noriko
authors.initials: N
authors.lastname: Sangu
authors.affiliation: Tokyo Women's Medical University Institute for Integrated Medical Sciences, Tokyo, Japan. Electronic address: shimojima.keiko@twmu.ac.jp.
authors.forename: Keiko
authors.initials: K
authors.lastname: Shimojima
authors.affiliation: Department of Pediatrics, Aichi Medical University, Nagakute, Japan. Electronic address: okumura.akihisa.479@mail.aichi-med-u.ac.jp.
authors.forename: Okumura
authors.initials: O
authors.lastname: Akihisa
authors.affiliation: Department of Oral and Maxillofacial Surgery, School of Medicine, Tokyo Women's Medical University, Tokyo, Japan. Electronic address: tando@oms.twmu.ac.jp.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Ando
authors.affiliation: Tokyo Women's Medical University Institute for Integrated Medical Sciences, Tokyo, Japan. Electronic address: yamamoto.toshiyuki@twmu.ac.jp.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Yamamoto
mesh_terms: D004252:DNA Mutational Analysis; D004569:Electroencephalography; D004828:Epilepsies, Partial / Q000235:genetics*; D020936:Epilepsy, Benign Neonatal / Q000235:genetics*; D005192:Family Health; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008565:Membrane Proteins / Q000235:genetics*; D009154:Mutation / Q000235:genetics*; D009419:Nerve Tissue Proteins / Q000235:genetics*; D014057:Tomography, X-Ray Computed
chemical_list: D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; C569370:PRRT2 protein, human
keywords: Benign familial infantile epilepsy (BFIE); Benign partial epilepsy in infancy (BPEI); Infantile convulsions and choreoathetosis syndrome (ICCA); Paroxysmal kinesigenic dyskinesia (PKD); Proline-rich transmembrane protein 2 (PRRT2)