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Yang L, You C, Qiu S, Yang X, Li Y, Liu F, Zhang D, Niu Y, Xu L, Xu N, Li X, Luo F, Yang J, Li B. Novel and de novo point and large microdeletion mutation in PRRT2-related epilepsy. Brain Behav 2020; 10:e01597. [PMID: 32237035 PMCID: PMC7218244 DOI: 10.1002/brb3.1597] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 02/12/2020] [Accepted: 02/25/2020] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Point and copy number variant mutations in the PRRT2 gene have been identified in a variety of paroxysmal disorders and different types of epilepsy. In this study, we analyzed the phenotypes and PRRT2-related mutations in Chinese epilepsy children. METHODS A total of 492 children with epilepsy were analyzed by whole exome sequencing (WES) and low-coverage massively parallel CNV sequencing (CNV-seq) to find the single nucleotide variants and copy number variations (CNVs). And quantitative polymerase chain reaction was utilized to verify the CNVs. Their clinical information was followed up. RESULTS We found PRRT2-related mutations in 19 patients (10 males and nine females, six sporadic cases and 13 family cases). Twelve point mutations, four whole gene deletion, and three 16p11.2 deletions were detected. The clinical features of 39 patients in 19 families included one early childhood myoclonic epilepsy (ECME), one febrile seizure (FS), two infantile convulsions with paroxysmal choreoathetosis (ICCA), six paroxysmal kinesigenic dyskinesias (PKD), 12 benign infantile epilepsy (BIE), and 17 benign familial infantile epilepsy (BFIE). All patients had normal brain MRI. Interictal EEG showed only one patient had generalized polyspike wave and five patients had focal transient discharges. Focal seizures originating in the frontal region were recorded in one patient, two from the temporal region, and two from the occipital region. Most patients were treated effectively with VPA or OXC, and the child with myoclonic seizures was not sensitive to antiepileptic drugs. CONCLUSION PRRT2 mutations can be inherited or de novo, mainly inherited. The clinical spectrum of PRRT2 mutation includes BIE, BFIE, ICCA, PKD, FS, and ECME. The PRRT2-related mutations contained point mutation, whole gene deletion and 16p11.2 deletions, and large microdeletion mutations mostly de novo. It is the first report of PRRT2 mutation found in ECME. Our report expands the mutation and clinical spectrum of PRRT2-related epilepsy.
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Affiliation(s)
- Li Yang
- Department of Pediatrics, Qilu Hospital of Shandong University, Jinan, China.,Department of Pediatrics, Linyi People's Hospital Affiliated to Shandong University, Linyi, China
| | - Cuiping You
- Central Laboratory, Linyi People's Hospital Affiliated to Shandong University, Linyi, China
| | - Shiyan Qiu
- Department of Pediatrics, Linyi People's Hospital Affiliated to Shandong University, Linyi, China
| | - Xiaofan Yang
- Department of Pediatrics, Qilu Hospital of Shandong University, Jinan, China
| | - Yufen Li
- Department of Pediatrics, Linyi People's Hospital Affiliated to Shandong University, Linyi, China
| | - Feng Liu
- Department of Neurology, Zibo Zhangdian Hospital of Traditional Chinese Medicine, Zibo, China
| | - Dongqing Zhang
- Department of Pediatrics, Qilu Hospital of Shandong University, Jinan, China
| | - Yue Niu
- Department of Pediatrics, Qilu Hospital of Shandong University, Jinan, China
| | - Liyun Xu
- Department of Pediatrics, Linyi People's Hospital Affiliated to Shandong University, Linyi, China.,Department of Pediatrics, Shandong medical college, Linyi, China
| | - Na Xu
- Department of Pediatrics, Linyi People's Hospital Affiliated to Shandong University, Linyi, China
| | - Xia Li
- Department of Pediatrics, Linyi People's Hospital Affiliated to Shandong University, Linyi, China
| | | | - Junli Yang
- Department of Pediatrics, Qilu Hospital of Shandong University, Jinan, China
| | - Baomin Li
- Department of Pediatrics, Qilu Hospital of Shandong University, Jinan, China
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Pavone P, Corsello G, Cho SY, Pappalardo XG, Ruggieri M, Marino SD, Jin DK, Marino S, Falsaperla R. PRRT2 gene variant in a child with dysmorphic features, congenital microcephaly, and severe epileptic seizures: genotype-phenotype correlation? Ital J Pediatr 2019; 45:159. [PMID: 31801583 PMCID: PMC6894132 DOI: 10.1186/s13052-019-0755-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2019] [Accepted: 11/25/2019] [Indexed: 12/22/2022] Open
Abstract
Background Mutations in Proline-rich Transmembrane Protein 2 (PRRT2) have been primarily associated with individuals presenting with infantile epilepsy, including benign familial infantile epilepsy, benign infantile epilepsy, and benign myoclonus of early infancy, and/or with dyskinetic paroxysms such as paroxysmal kinesigenic dyskinesia, paroxysmal non-kinesigenic dyskinesia, and exercise-induced dyskinesia. However, the clinical manifestations of this disorder vary widely. PRRT2 encodes a protein expressed in the central nervous system that is mainly localized in the pre-synaptic neurons and is involved in the modulation of synaptic neurotransmitter release. The anomalous function of this gene has been proposed to cause dysregulation of neuronal excitability and cerebral disorders. Case presentation We hereby report on a young child followed-up for three years who presents with a spectrum of clinical manifestations such as congenital microcephaly, dysmorphic features, severe intellectual disability, and drug-resistant epileptic encephalopathy in association with a synonymous variant in PRRT2 gene (c.501C > T; p.Thr167Ile) of unknown clinical significance variant (VUS) revealed by diagnostic exome sequencing. Conclusion Several hypotheses have been advanced on the specific role that PRRT2 gene mutations play to cause the clinical features of affected patients. To our knowledge, the severe phenotype seen in this case has never been reported in association with any clinically actionable variant, as the missense substitution detected in PRRT2 gene. Intriguingly, the same mutation was reported in the healthy father: the action of modifying factors in the affected child may be hypothesized. The report of similar observations could extend the spectrum of clinical manifestations linked to this mutation.
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Affiliation(s)
- Piero Pavone
- Department of Pediatrics, University-Hospital "Policlinico-Vittorio Emanuele", University of Catania, Via Santa Sofia 78, 95124, Catania, Italy.
| | | | - Sung Yoon Cho
- Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
| | - Xena Giada Pappalardo
- National Council of Research, CNR, Institute for Research and for Biomedicine Innovation (IRIB) unit of Catania, Catania, Italy
| | - Martino Ruggieri
- Department of Clinical and Experimental Medicine, Section of Pediatrics and Child Neuropsychiatry, University of Catania, Catania, Italy
| | - Simona Domenica Marino
- Department of Pediatrics, University-Hospital "Policlinico-Vittorio Emanuele", University of Catania, Via Santa Sofia 78, 95124, Catania, Italy
| | - Dong Kyu Jin
- Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
| | - Silvia Marino
- Department of Pediatrics, University-Hospital "Policlinico-Vittorio Emanuele", University of Catania, Via Santa Sofia 78, 95124, Catania, Italy
| | - Raffaele Falsaperla
- Department of Pediatrics, University-Hospital "Policlinico-Vittorio Emanuele", University of Catania, Via Santa Sofia 78, 95124, Catania, Italy
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