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Lo AC, Rajan N, Gastaldo D, Telley L, Hilal ML, Buzzi A, Simonato M, Achsel T, Bagni C. Absence of RNA-binding protein FXR2P prevents prolonged phase of kainate-induced seizures. EMBO Rep 2021; 22:e51404. [PMID: 33779029 PMCID: PMC8024897 DOI: 10.15252/embr.202051404] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 01/26/2021] [Accepted: 01/29/2021] [Indexed: 12/26/2022] Open
Abstract
Status epilepticus (SE) is a condition in which seizures are not self-terminating and thereby pose a serious threat to the patient's life. The molecular mechanisms underlying SE are likely heterogeneous and not well understood. Here, we reveal a role for the RNA-binding protein Fragile X-Related Protein 2 (FXR2P) in SE. Fxr2 KO mice display reduced sensitivity specifically to kainic acid-induced SE. Immunoprecipitation of FXR2P coupled to next-generation sequencing of associated mRNAs shows that FXR2P targets are enriched in genes that encode glutamatergic post-synaptic components. Of note, the FXR2P target transcriptome has a significant overlap with epilepsy and SE risk genes. In addition, Fxr2 KO mice fail to show sustained ERK1/2 phosphorylation induced by KA and present reduced burst activity in the hippocampus. Taken together, our findings show that the absence of FXR2P decreases the expression of glutamatergic proteins, and this decrease might prevent self-sustained seizures.
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Affiliation(s)
- Adrian C Lo
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
| | - Nicholas Rajan
- Department of Neurosciences and Leuven Brain Institute, KU Leuven, Leuven, Belgium
| | - Denise Gastaldo
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
| | - Ludovic Telley
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
| | - Muna L Hilal
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
| | - Andrea Buzzi
- Department of Neuroscience and Rehabilitation, University of Ferrara, Ferrara, Italy
| | - Michele Simonato
- Department of Neuroscience and Rehabilitation, University of Ferrara, Ferrara, Italy.,Division of Neuroscience, IRCCS San Raffaele Hospital, Milan, Italy
| | - Tilmann Achsel
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland
| | - Claudia Bagni
- Department of Fundamental Neurosciences, University of Lausanne, Lausanne, Switzerland.,Department of Neurosciences and Leuven Brain Institute, KU Leuven, Leuven, Belgium.,Department of Biomedicine and Prevention, University of Rome "Tor Vergata", Rome, Italy
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Challenges in the clinical interpretation of small de novo copy number variants in neurodevelopmental disorders. Gene 2019; 706:162-171. [PMID: 31085274 DOI: 10.1016/j.gene.2019.05.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 03/27/2019] [Accepted: 05/03/2019] [Indexed: 12/17/2022]
Abstract
In clinical genetics, the need to discriminate between benign and pathogenic variants identified in patients with neurodevelopmental disorders is an absolute necessity. Copy number variants (CNVs) of small size can enable the identification of genes that are critical for neurologic development. However, assigning a definite association with a specific disorder is a difficult task. Among 328 trios analyzed over seven years of activity in a single laboratory, we identified 19 unrelated patients (5.8%) who carried a small (<500 kb) de novo CNV. Four patients had an additional independent de novo CNV. Nine had a variant that could be assigned as definitely pathogenic, whereas the remaining CNVs were considered as variants of unknown significance (VUS). We report clinical and molecular findings of patients harboring VUS. We reviewed the medical literature available for genes impacted by CNVs, obtained the probability of truncating loss-of-function intolerance, and compared overlapping CNVs reported in databases. The classification of small non-recurrent CNVs remains difficult but, among our findings, we provide support for a role of SND1 in the susceptibility of autism, describe a new case of the rare 17p13.1 microduplication syndrome, and report an X-linked duplication involving KIF4A and DLG3 as a likely cause of epilepsy.
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Leka-Emiri S, Petrou V, Manolakos E, Thomaidis L, Fotinou A, Vlachopapadopoulou E, Michalacos S. 17p13.1 Microduplication Syndrome in a Child, Familial Short Stature, and Growth Hormone Deficiency: A Case Report and Review of the Literature. Mol Syndromol 2019; 9:300-305. [PMID: 30800046 DOI: 10.1159/000494681] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/02/2018] [Indexed: 11/19/2022] Open
Abstract
To date, 6 cases of 17p13.1 microduplications have been described in the literature. Intellectual disability is the core feature, together with minor facial dysmorphisms and obesity. We describe the first case of a young patient with a maternally inherited microduplication in 17p13.1 presenting with growth hormone deficiency. The boy was addressed to the endocrine division for growth retardation (weight and height <3rd percentile). Besides minor facial dysmorphisms, physical and neurological examinations were normal except for motor dyspraxia. Basic blood tests and endocrinological investigations were normal, but IGF1 levels were low for his age. Growth hormone deficiency was confirmed. Hypothalamic pituitary MRI was normal. His karyotype was 46XY. Array-CGH analysis detected a 422-kb copy number gain in the spanning region 17p13.1 inherited from his mother. Although familial short stature is considered a "normal" variation of growth retardation, hormonal and genetic investigation is essential in the etiological diagnosis.
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Affiliation(s)
- Sofia Leka-Emiri
- Department of Endocrinology, Growth and Development, Athens, Greece
| | - Vassilios Petrou
- Department of Endocrinology, Growth and Development, Athens, Greece
| | - Emmanouil Manolakos
- Department of Access to Genome (ATG P.C.), Clinical Laboratory Genetics, Athens, Greece
| | - Loretta Thomaidis
- Department of Developmental Assessment Unit, Department of Pediatrics, P&A Kyriakou Children's Hospital, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece
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