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Zhang L, Wan ZX, Zhu JY, Liu HJ, Sun J, Zou XH, Zhang T, Li Y. A Girl with PRRT2 Mutation Presenting with Benign Familial Infantile Seizures Followed by Autistic Regression. Case Rep Pediatr 2024; 2024:5539799. [PMID: 38406554 PMCID: PMC10890899 DOI: 10.1155/2024/5539799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 01/10/2024] [Accepted: 01/24/2024] [Indexed: 02/27/2024] Open
Abstract
Benign familial infantile seizure (BFIS) is an autosomal dominant infantile-onset epilepsy syndrome with a typically benign prognosis. It is commonly associated with heterozygous mutations of the PRRT2 gene located on chromosome 16p11.2. The frameshift heterozygous mutation (c.649dupC, p.Arg217Profs∗8) in PRRT2 is responsible for the majority of BFIS cases. In this report, we present a rare case of a girl with a confirmed clinical and genetic diagnosis of BFIS due to a frameshift heterozygous mutation in PRRT2 (c.649dupC). She exhibited typical neurodevelopment until 15 months of age, followed by an unexpected severe autistic regression. In addition to BFIS, PRRT2 mutations are also associated with paroxysmal kinesigenic dyskinesia (PKD) and infantile convulsions and paroxysmal choreoathetosis (ICCA), indicating a complex genotype-phenotype heterogeneity in PRRT2 mutations. This clinical observation highlights the possibility that BFIS patients with PRRT2 mutations may not always have a benign neurodevelopmental prognosis, emphasizing the need for long-term clinical follow-up.
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Affiliation(s)
- Li Zhang
- Research Center for Child Health, Department of Child Health Care, Key Laboratory of Birth Regulation and Control Technology of National Health Commission of China, Shandong Provincial Maternal and Child Health Care Hospital Affiliated to Qingdao University, Jinan, China
| | - Zhen-Xia Wan
- Neonatal Intensive Care Unit, Key Laboratory of Birth Regulation and Control Technology of National Health Commission of China, Shandong Provincial Maternal and Child Health Care Hospital Affiliated to Qingdao University, Jinan, China
| | - Jin-Yi Zhu
- Affiliated Hospital of Weifang Medical University, School of Clinical Medicine, Weifang Medical University, Weifang, China
| | - Hui-Juan Liu
- Research Center for Child Health, Department of Child Health Care, Key Laboratory of Birth Regulation and Control Technology of National Health Commission of China, Shandong Provincial Maternal and Child Health Care Hospital Affiliated to Qingdao University, Jinan, China
| | - Jin Sun
- Department of Child Health Care, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital, Jinan, China
| | - Xiao-Hui Zou
- Department of Child Health Care, The First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital, Jinan, China
| | - Ting Zhang
- Research Center for Child Health, Department of Child Health Care, Key Laboratory of Birth Regulation and Control Technology of National Health Commission of China, Shandong Provincial Maternal and Child Health Care Hospital Affiliated to Qingdao University, Jinan, China
| | - Yan Li
- Research Center for Child Health, Department of Child Health Care, Key Laboratory of Birth Regulation and Control Technology of National Health Commission of China, Shandong Provincial Maternal and Child Health Care Hospital Affiliated to Qingdao University, Jinan, China
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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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A novel PRRT2 pathogenic variant in a family with paroxysmal kinesigenic dyskinesia and benign familial infantile seizures. Cold Spring Harb Mol Case Stud 2018; 4:mcs.a002287. [PMID: 29167286 PMCID: PMC5793775 DOI: 10.1101/mcs.a002287] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2017] [Accepted: 11/02/2017] [Indexed: 12/30/2022] Open
Abstract
Paroxysmal kinesigenic dyskinesia (PKD) is a rare neurological disorder characterized by recurrent attacks of dyskinetic movements without alteration of consciousness that are often triggered by the initiation of voluntary movements. Whole-exome sequencing has revealed a cluster of pathogenic variants in PRRT2 (proline-rich transmembrane protein), a gene with a function in synaptic regulation that remains poorly understood. Here, we report the discovery of a novel PRRT2 pathogenic variant inherited in an autosomal dominant pattern in a family with PKD and benign familial infantile seizures (BFIS). After targeted Sanger sequencing did not identify the presence of previously described PRRT2 pathogenic variants, we carried out whole-exome sequencing in the proband and her affected paternal grandfather. This led to the discovery of a novel PRRT2 variant, NM_001256442:exon3:c.C959T/NP_660282.2:p.A320V, altering an evolutionarily conserved alanine at the amino acid position 320 located in the M2 transmembrane region. Sanger sequencing further confirmed the presence of this variant in four affected family members (paternal grandfather, father, brother, and proband) and its absence in two unaffected ones (paternal grandmother and mother). This newly found variant further reinforces the importance of PRRT2 in PKD, BFIS, and possibly other movement disorders. Future functional studies using animal models and human pluripotent stem cell models will provide new insights into the role of PRRT2 and the significance of this variant in regulating neural development and/or function.
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