scholarly journals De novo hotspot variants in CYFIP2 cause early‐onset epileptic encephalopathy

2018 ◽  
Vol 83 (4) ◽  
pp. 794-806 ◽  
Author(s):  
Mitsuko Nakashima ◽  
Mitsuhiro Kato ◽  
Kazushi Aoto ◽  
Masaaki Shiina ◽  
Hazrat Belal ◽  
...  
2020 ◽  
Author(s):  
Zhi Yi ◽  
Zhenfeng Song ◽  
Jiao Xue ◽  
Chengqing Yang ◽  
Fei Li ◽  
...  

Abstract Background: Developmental and epileptic encephalopathies (DEE) are a heterogeneous group of severe disorders which are characterized by early-onset, refractory seizures and developmental slowing or regression. Genetic variations are significant causes for them. De novo variants in an increasing number of candidate genes have been found to be causal. YWHAG gene variants have been reported to cause developmental and epileptic encephalopathy 56 (DEE56). Case presentation: Here, we report a novel heterozygous missense variant c.170G>A (p.R57H) in YWHAG gene cause early-onset epilepsy in a Chinese family. Both the proband and his mother exhibit early onset seizures, intellectual disability, developmental delay. While the proband achieve seizure control with sodium valproate, his mother's seizures were not well controlled. Conclusions: Our report further confirming the haploinsufficiency of YWHAG results in developmental and epileptic encephalopathies.


2017 ◽  
Vol 39 (3) ◽  
pp. 256-260 ◽  
Author(s):  
Tomokazu Kimizu ◽  
Yukitoshi Takahashi ◽  
Taikan Oboshi ◽  
Asako Horino ◽  
Takayoshi Koike ◽  
...  

2017 ◽  
Vol 3 (1) ◽  
pp. 81-85 ◽  
Author(s):  
Satoshi Akamine ◽  
Noriaki Sagata ◽  
Yasunari Sakai ◽  
Takahiro A. Kato ◽  
Takeshi Nakahara ◽  
...  

Author(s):  
Chiara Klöckner ◽  
◽  
Heinrich Sticht ◽  
Pia Zacher ◽  
Bernt Popp ◽  
...  

Brain ◽  
2019 ◽  
Vol 142 (7) ◽  
pp. 1938-1954 ◽  
Author(s):  
Ciria C Hernandez ◽  
Wenshu XiangWei ◽  
Ningning Hu ◽  
Dingding Shen ◽  
Wangzhen Shen ◽  
...  

Abstract We performed next generation sequencing on 1696 patients with epilepsy and intellectual disability using a gene panel with 480 epilepsy-related genes including all GABAA receptor subunit genes (GABRs), and we identified six de novo GABR mutations, two novel GABRA5 mutations (c.880G>T, p.V294F and c.1238C>T, p.S413F), two novel GABRA1 mutations (c.778C>T, p.P260S and c.887T>C, p.L296S/c.944G>T, p.W315L) and two known GABRA1 mutations (c.335G>A, p.R112Q and c.343A>G, p.N115D) in six patients with intractable early onset epileptic encephalopathy. The α5(V294F and S413F) and α1(P260S and L296S/W315L) subunit residue substitutions were all in transmembrane domains, while the α1(R112Q and N115R) subunit residue substitutions were in the N-terminal GABA binding domain. Using multidisciplinary approaches, we compared effects of mutant GABAA receptor α5 and α1 subunits on the properties of recombinant α5β3γ2 and α1β3γ2 GABAA receptors in both neuronal and non-neuronal cells and characterized their effects on receptor clustering, biogenesis and channel function. GABAA receptors containing mutant α5 and α1 subunits all had reduced cell surface and total cell expression with altered endoplasmic reticulum processing, impaired synaptic clustering, reduced GABAA receptor function and decreased GABA binding potency. Our study identified GABRA5 as a causative gene for early onset epileptic encephalopathy and expands the mutant GABRA1 phenotypic spectrum, supporting growing evidence that defects in GABAergic neurotransmission contribute to early onset epileptic encephalopathy phenotypes.


2010 ◽  
Vol 13 (2) ◽  
pp. 168-178 ◽  
Author(s):  
Rose White ◽  
Gladys Ho ◽  
Swetlana Schmidt ◽  
Ingrid E. Scheffer ◽  
Alexandra Fischer ◽  
...  

AbstractRett syndrome (RTT) is a severe neurodevelopmental disorder affecting females almost exclusively and is characterized by a wide spectrum of clinical manifestations. Mutations in the X-linked methyl-CpG-binding protein 2 (MECP2) gene have been found in up to 95% of classical RTT cases and a lesser proportion of atypical cases. Recently, mutations in another X-linked gene, CDKL5 (cyclin-dependent kinase-like 5) have been found to cause atypical RTT, in particular the early onset seizure (Hanefeld variant) and one female with autism. In this study we screened several cohorts of children for CDKL5 mutations, totaling 316 patients, including individuals with a clinical diagnosis of RTT but who were negative for MECP2 mutations (n = 102), males with X-linked mental retardation (n = 9), patients with West syndrome (n = 52), patients with autism (n = 59), patients with epileptic encephalopathy (n = 33), patients with Aicardi syndrome (n = 7) and other patients with intellectual disability with or without seizures (n = 54). In all, seven polymorphic variations and four de novo mutations (c.586C>T [p.S196L]; c.58G>C [p.G20R]; c.2504delC [p.P835fs]; deletion of exons 1 - 3) were identified, and in all instances of the latter the clinical phenotype was that of an epileptic encephalopathy. These results suggest that pathogenic CDKL5 mutations are unlikely to be identified in the absence of severe early-onset seizures and highlight the importance of screening for large intragenic and whole gene deletions.


2014 ◽  
Vol 5 (1) ◽  
Author(s):  
Hongjie Yuan ◽  
Kasper B. Hansen ◽  
Jing Zhang ◽  
Tyler Mark Pierson ◽  
Thomas C. Markello ◽  
...  

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