scholarly journals De novo SCN1A géndeletio terápiarezisztens Dravet-szindrómában

2015 ◽  
Vol 156 (49) ◽  
pp. 2009-2012 ◽  
Author(s):  
Judit Bene ◽  
Kinga Hadzsiev ◽  
Katalin Komlósi ◽  
Erzsébet Kövesdi ◽  
Petra Mátyás ◽  
...  

Severe myoclonic epilepsy in infancy (Dravet’s syndrome) is a very rare form of epilepsy. Mutations of SCN1A gene encoding voltage-gated sodium channel alpha-1 subunit are major causes of the autosomal dominant disorder. Most cases are associated with a de novo point mutation, but some patients have copy number variations. The protein encoded by the SCN1A gene plays a role in the generation and propagation of action potentials. Loss of function caused by the majority of gene mutations leads to hyperexcitability of the neuronal network that finally results in the formation of the epileptic seizures. Molecular genetic test for copy number variations of SCN1A gene is available in the department of the authors since 2013 besides sequencing analysis of the whole gene. This article presents the case of a 7-year-old patient with two years of recorded patient history outside of the author’s department. Molecular genetic test, which detected a de novo SCN1A gene deletion in heterozygous form, revealed SCN1A gene associated monogenic epileptic syndrome being in the genetic background of therapy-resistant seizures. Orv. Hetil., 2015, 156(49), 2009–2012.

Diagnostics ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 415
Author(s):  
Kuntharee Traisrisilp ◽  
Wisit Chankhunaphas ◽  
Rekwan Sittiwangkul ◽  
Chureerat Phokaew ◽  
Vorasuk Shotelersuk ◽  
...  

CHARGE syndrome is a rare autosomal dominant disorder, associated with coloboma (C), heart defects (H), choanal atresia (A), retardation of growth and/or central nervous system (R), genitourinary anomalies (G) and ear abnormalities (E). Prenatal diagnosis of the syndrome is very rare but may be suspected when a combination of such abnormalities is identified. We describe a prenatally suspected case of CHARGE syndrome due to unique findings of cardiac defects (DORV) in combination with minor clues, including a structurally malformed ear with persistent non-response to an acoustic stimulation (which has never been prenatally described elsewhere), renal malrotation and growth restriction. Postnatal diagnosis was made based on confirmation of the prenatal findings and additional specific findings of bilateral coloboma, choanal atresia and ear canal stenosis. Finally, molecular genetic testing by whole exome sequencing of the neonate and her parents revealed a novel de novo heterozygous frameshift c.3506_3509dup variant in the CHD7 gene, confirming the clinical diagnosis of CHARGE syndrome. In conclusion, we describe unique prenatal features of CHARGE syndrome. Educationally, this is one of the rare examples of CHARGE syndrome, comprising all of the six specific anomalies as originally described; it is also supported by the identification of a specific genetic mutation. The identified genetic variant has never been previously reported, thereby expanding the mutational spectrum of CHD7. Finally, this case can inspire prenatal sonographers to increase awareness of subtle or minor abnormalities as genetic sonomarkers.


2007 ◽  
Vol 9 (1) ◽  
pp. 95-98 ◽  
Author(s):  
Matthew J. McGinniss ◽  
Rebecca Chen ◽  
Victoria M. Pratt ◽  
Arlene Buller ◽  
Franklin Quan ◽  
...  

2021 ◽  
Author(s):  
Sean Bergin ◽  
Fang Zhao ◽  
Adam P Ryan ◽  
Carolin A Müller ◽  
Conrad A Nieduszynski ◽  
...  

Flippases and floppases are two classes of proteins that have opposing functions in the maintenance of lipid asymmetry of the plasma membrane. Flippases translocate lipids from the exoplasmic leaflet to the cytosolic leaflet, and floppases act in the opposite direction. Phosphatidylcholine (PC) is a major component of the eukaryotic plasma membrane and is asymmetrically distributed, being more abundant in the exoplasmic leaflet. Here we show that gene amplification of a putative PC floppase or double disruption of two PC flippases in the pathogenic yeast Candida parapsilosis results in resistance to miltefosine, an alkylphosphocholine drug that affects PC metabolism that has recently been granted orphan drug designation approval by the US FDA for treatment of invasive candidiasis. We analysed the genomes of 170 C. parapsilosis isolates and found that 107 of them have copy number variations (CNVs) at the RTA3 gene. RTA3 encodes a putative PC floppase whose deletion is known to increase the inward translocation of PC in Candida albicans. RTA3 copy number ranges from 2 to >40 across the C. parapsilosis isolates. Interestingly, 16 distinct CNVs with unique endpoints were identified, and phylogenetic analysis shows that almost all of them have originated only once. We found that increased copy number of RTA3 correlates with miltefosine resistance. Additionally, we conducted an adaptive laboratory evolution experiment in which two C. parapsilosis isolates were cultured in increasing concentrations of miltefosine over 26 days. Two genes, CPAR2_303950 and CPAR2_102700, gained homozygous protein-disrupting mutations in the evolved strains and code for putative PC flippases homologous to S. cerevisiae DNF1. Our results indicate that alteration of lipid asymmetry across the plasma membrane is a key mechanism of miltefosine resistance. We also find that C. parapsilosis is likely to gain resistance to miltefosine rapidly, because many isolates carry loss-of-function alleles in one of the flippase genes.


2021 ◽  
Vol 49 (8) ◽  
pp. 030006052110358
Author(s):  
Lin Qiao ◽  
Yuting Yang ◽  
Dongmei Yue

Objective Tuberous sclerosis (TSC) is an autosomal dominant disorder, often detected during childhood. We present the results of genetic testing in a newborn with suspected TSC. Methods A newborn with no specific clinical manifestations of TSC showed evidence of TSC on magnetic resonance imaging and echocardiography. Next-generation sequencing (NGS) and multiple ligation-dependent probe amplification (MLPA) of the TSC1 and TSC2 gene exons were carried out to confirm the diagnosis. Results The results of MLPA were negative, but NGS showed a heterozygous mutation in the TSC1 gene comprising insertion of a T residue at c.2165 (exon 17) to c.2166 (exon 17), indicating a loss of function mutation. These results were verified by Sanger sequencing. This genetic change was present in the newborn but the parental genotypes were wild-type, indicating a de novo mutation. Conclusions In this case, a case of TSC caused by a heterozygous mutation in the TSC1 gene was confirmed by NGS sequencing. This indicates the suitability of genetic testing for the early diagnosis of clinically rare and difficult-to-diagnose diseases, to guide clinical treatment.


2020 ◽  
Vol 21 (21) ◽  
pp. 8247
Author(s):  
Alina Christine Hilger ◽  
Gabriel Clemens Dworschak ◽  
Heiko Martin Reutter

The treatment of major birth defects are key concerns for child health. Hitherto, for the majority of birth defects, the underlying cause remains unknown, likely to be heterogeneous. The implicated mortality and/or reduced fecundity in major birth defects suggest a significant fraction of mutational de novo events among the affected individuals. With the advent of systematic array-based molecular karyotyping, larger cohorts of affected individuals have been screened over the past decade. This review discusses the identification of disease-causing copy-number variations (CNVs) among individuals with different congenital malformations. It highlights the differences in findings depending on the respective congenital malformation. It looks at the differences in findings of CNV analysis in non-isolated complex congenital malformations, associated with central nervous system malformations or intellectual disabilities, compared to isolated single organ-system malformations. We propose that the more complex an organ system is, and the more genes involved during embryonic development, the more likely it is that mutational de novo events, comprising CNVs, will confer to the expression of birth defects of this organ system.


2018 ◽  
Vol 5 ◽  
pp. 2329048X1879820
Author(s):  
Miriam Kessi ◽  
Jing Peng ◽  
Lifen Yang ◽  
Haolin Duan ◽  
Yulin Tang ◽  
...  

1q43q44 microdeletion syndrome is characterized by intellectual disability/global developmental delay, epilepsy, dysmorphic facies, stereotypic movement, language delay, recurrent infections, dental anomalies, and hand and foot anomalies. Microcephaly and corpus callosum dysplasia are present in some cases depending on gene content. 3q29 microduplication syndrome is characterized by intellectual disability, language delay, microcephaly, and dental anomalies. We report the first case with 4 de novo copy number variations with clinical features which overlap 1q43q44 microdeletion and 3q29 microduplication syndromes. Our case presented with global developmental delay, epilepsy, recurrent infections, stereotypic movements, speech delay, microcephaly, facial dysmorphism, bilateral clinodactyly, and small puffy feet with metatarsus varus; however, she had no corpus callosum dysplasia. Our case highlights the role of multiple copy number variations in the occurrence of a certain phenotype. Moreover, it supports the theory that the loss of HNRNPU gene function cannot explain the occurrence of microcephaly and abnormalities of the corpus callosum in 1q43q44 microdeletion syndrome.


2012 ◽  
Vol 15 (6) ◽  
pp. 444-449 ◽  
Author(s):  
Maren T. Scheuner ◽  
◽  
Maria Orlando Edelen ◽  
Lee H. Hilborne ◽  
Ira M. Lubin

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 1761-1761
Author(s):  
Andrew M. Intlekofer ◽  
Venkatraman E. Sheshan ◽  
Ross L. Levine ◽  
Andrew D. Zelenetz ◽  
Julie Teruya-Feldstein ◽  
...  

Abstract Whole genome and exome sequencing studies have identified numerous genomic alterations in DLBCL, but these methods have limited applicability for the clinical care of lymphoma patients due to cost, specific tissue requirements, and laborious bioinformatic analysis. FoundationOne-Heme (FOH) is a novel next-generation sequencing platform designed to provide targeted assessment of the genomic landscape of hematologic malignancies, including identification of mutations within specific genes, copy number changes, and translocations. FOH can be performed on small quantities of formalin-fixed paraffin-embedded (FFPE) tissue, detect rare variants due to extensive depth of sequencing coverage, and rapidly provide results via streamlined bioinformatic interpretation. Here we report the first experience using this novel platform to evaluate the genetic landscape of DLBCL. Genomic DNA and total RNA were isolated from FFPE tissue on a cohort of 53 cases of DLBCL, including de novo (n=30), relapsed/refractory (n=12), and large cell transformation from low-grade lymphoma (n=11). The cohort included 25 cases with combined MYC and BCL2 overexpression by IHC (criteria for positivity: >40% MYC, >70% BCL2), of which only one had a known translocation involving MYC. Adaptor ligated sequencing libraries were captured by solution hybridization using two custom bait sets targeting 374 cancer-related genes and 24 genes frequently rearranged for DNA-seq, and 258 frequently-rearranged genes for RNA-seq. All captured libraries were sequenced to high depth (Illumina HiSeq), averaging >658x for DNA and >20,000,000 total pairs for RNA, to enable the sensitive and specific detection of genomic alterations. Significant non-synonomous variants were identified as mutations from the COSMIC database, amplifications of established oncogenes, or homozygous deletions and/or clear loss-of-function mutations of known tumor suppressors. The DNA sequencing component of FOH detected translocations in BCL2, BCL6, and MYC, while the RNA sequencing component detected fusion transcripts involving BLC6 and MYC, in agreement with independent cytogenetic analysis via karyotype and FISH where available. The assay detected copy number alterations of 44 different genes, most commonly amplification of REL (15%) or loss of CDKN2A/CDKN2B (17%). The most frequent alterations of known significance are detailed in Figure 1. The most commonly altered gene was CDKN2A, exhibiting either homozygous deletion or loss of function mutation in 28% of cases. Chromatin modifying factors (e.g. MLL2, CREBBP, EZH2) represented the most frequently altered biologic category with alterations occurring in >50% of cases. Recurrent alterations in components of the Notch pathway (NOTCH1/2/4, FBXW7, SPEN), each predicted to activate the pathway, were identified in 23% of cases. Cell-of-origin was determined as per the Hans model using IHC for CD10, BCL6, and IRF4/MUM1; CD79B mutations were detected exclusively in non-GCB and EZH2 mutations were found exclusively in GCB-phenotype cases. Furthermore, IHC MYC+/BCL2+ de novo DLBCL cases (n=11) exhibited more frequent hypermutation of PIM1 (46%) compared with the 19 cases of IHC MYC-/BCL2- de novo DLBCL (11%). When comparing the various clinical categories, we found that mutations in tumor suppressors were significantly more common in relapsed/refractory than de novo DLBCL (47% vs 75%, p=0.02). Alterations in TP53 were most frequently observed in transformed lymphoma (55%). Our results demonstrate the feasibility of using a targeted next-generation sequencing platform on FFPE clinical specimens from patients with DLBCL as a means of providing an integrated analysis of gene mutations, copy number alterations, and translocations. This streamlined approach combines multiple molecular and cytogenetic tests into a single platform and uses a small amount of tissue to perform a multifaceted assessment of genomic alterations with potential diagnostic, prognostic, and therapeutic implications. Future efforts will be directed at analyzing additional cases of DLBCL to better establish the biologic and clinical significance of the observed genetic alterations, and to prospectively incorporate this novel platform to select patients for mechanism-based targeted therapy. Disclosures: Intlekofer: Foundation Medicine, Inc: Consultancy. Levine:Foundation Medicine, Inc: Consultancy. Zelenetz:Foundation Medicine, Inc: Consultancy. Palomba:Foundation Medicine, Inc: Consultancy. van den Brink:Foundation Medicine, Inc: Consultancy. Brennan:Foundation Medicine, Inc: Employment. Young:Foundation Medicine, Inc: Employment. He:Foundation Medicine, Inc: Employment. Nahas:Foundation Medicine, Inc: Employment. Yelensky:Foundation Medicine, Inc: Employment. Otto:Foundation Medicine, Inc: Employment. Lipson:Foundation Medicine, Inc: Employment. Stephens:Foundation Medicine, Inc: Employment. Miller:Foundation Medicine, Inc: Employment. Younes:Foundation Medicine, Inc: Consultancy.


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