scholarly journals Whole-Exome Sequencing Identified a De Novo Mutation of Junction Plakoglobin (p.R577C) in a Chinese Patient with Arrhythmogenic Right Ventricular Cardiomyopathy

2019 ◽  
Vol 2019 ◽  
pp. 1-6
Author(s):  
Lv Liu ◽  
Chan Chen ◽  
YaLi Li ◽  
Rong Yu
Keyword(s):  
Right Ventricular ◽  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Connexin 43 ◽  
De Novo ◽  
Arrhythmogenic Right Ventricular Cardiomyopathy ◽  
Chinese Patient ◽  
De Novo Mutation ◽  
Ventricular Cardiomyopathy ◽  
Whole Exome

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a rare and potentially life-threatening disorder of the heart. The clinical spectrum of ARVC includes myocyte loss and fibro-fatty tissue replacement. With the progress of ARVC, the patient can present serious ventricular arrhythmias, heart failure, and even sudden cardiac death. Previous studies have demonstrated that desmosomes and intermediate junctions play a crucial role in the generation and development of ARVC. In this study, we enrolled a Chinese patient with suspicious ARVC. The patient suffered from right ventricular enlargement and less thickening of right ventricular wall. ECG record showed an epsilon wave. However, there was no obvious symptom in his parents. After whole-exome sequencing and data filtering, we identified a de novo mutation (c.1729C>T/p.R577C) of junction plakoglobin (JUP) in this patient. Bioinformatics programs predicted that this mutation was deleterious. Western blot revealed that, compared to cells transfected with WT plasmids, the expressions of desmoglein 2 (DSG2) and Connexin 43 were decreased overtly in cells transfected with the mutant plasmid. Previous studies have proven that the reduction of DSG2 and Connexin 43 may disturb the stability of desmosomes. In this research, we reported a novel de novo mutation (c.1729C>T/p.R577C) of JUP in a Chinese patient with suspicious ARVC. Functional research further confirmed the pathogenicity of this novel mutation. Our study expanded the spectrum of JUP mutations and may contribute to the genetic diagnosis and counseling of patients with ARVC.

A de novo mutation of SMYD1 (p.F272L) is responsible for hypertrophic cardiomyopathy in a Chinese patient

2019 ◽  
Vol 57 (4) ◽  
pp. 532-539 ◽  
Author(s):  
Liang-Liang Fan ◽  
Dong-Bo Ding ◽  
Hao Huang ◽  
Ya-Qin Chen ◽  
Jie-Yuan Jin ◽  
...  
Keyword(s):  
Hypertrophic Cardiomyopathy ◽  
Western Blot ◽  
Exome Sequencing ◽  
Real Time ◽  
Whole Exome Sequencing ◽  
De Novo ◽  
Left Ventricular ◽  
Chinese Patient ◽  
De Novo Mutation ◽  
Whole Exome

Abstract Background Hypertrophic cardiomyopathy (HCM) is a serious disorder and one of the leading causes of mortality worldwide. HCM is characterized as left ventricular hypertrophy in the absence of any other loading conditions. In previous studies, mutations in at least 50 genes have been identified in HCM patients. Methods In this research, the genetic lesion of an HCM patient was identified by whole exome sequencing. Real-time polymerase chain reaction (PCR), immunofluorescence and Western blot were used to analyze the effects of the identified mutation. Results According to whole exome sequencing, we identified a de novo mutation (c.814T>C/p.F272L) of SET and MYND domain containing histone methyltransferase 1 (SMYD1) in a Chinese patient with HCM exhibiting syncope. We then generated HIS-SMYD1-pcDNA3.1+ (WT and c.814T>C/p.F272L) plasmids for transfection into AC16 cells to functionalize the mutation. The immunofluorescence experiments indicated that this mutation may block the SMYD1 protein from entering the nucleus. Both Western blot and real-time PCR revealed that, compared with cells transfected with WT plasmids, the expression of HCM-associated genes such as β-myosin heavy chains, SMYD1 chaperones (HSP90) and downstream targets including TGF-β were all disrupted in cells transfected with the mutant plasmid. Previous studies have demonstrated that SMYD1 plays a crucial role in sarcomere organization and heart development. Conclusions This novel mutation (c.814T>C/p.F272L) may be the first identified disease-causing mutation of SMYD1 in HCM patients worldwide. Our research expands the spectrum of HCM-causing genes and contributes to genetic counseling for HCM patients.

Whole Exome Analysis of Relapsing Patients with Acute Promyelocytic Leukemia

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 2892-2892 ◽  
Author(s):  
Cecile Bally ◽  
Jacqueline Lehmann-Che ◽  
Bruno Cassinat ◽  
Lionel Ades ◽  
Eric Letouze ◽  
...  
Keyword(s):  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Research Funding ◽  
De Novo ◽  
Lymphoblastic Leukemia ◽  
Mapk Signaling ◽  
Copy Number Variations ◽  
Leukemic Cells ◽  
De Novo Mutation ◽  
Whole Exome

Abstract Background : APL is, in the vast majority of cases, driven by t(15 ;17) translocation, which leads to PML/RARA rearrangement. Remarkably, APL is an uncommon genetically simple disease and only few additional alterations, cooperating with PML/RAR, have been described at diagnostic (Welch et al, Cell 2012). Most APL can be cured with targeted therapy combining all-trans retinoic acid (ATRA) and chemotherapy (CT). However, genetic mechanisms underlying the 10-15% relapses observed with this regimen remain unclear. The goal of the present study was to identify mutations that cooperate with PML/RAR and those responsible for acquired resistance to ATRA-CT treatment in APL patients by whole-exome sequencing of diagnostic/ remission/relapse trios. Methods: Newly diagnosed APL patients included in clinical trials of the French Swiss Belgian APL group between 1994 and 2008, treated with ATRA-CT, before the introduction of first-line ATO, who experienced at least one relapse and had adequate material, were studied. We collected retrospectively 64 samples from 23 patients, including 23 diagnostic samples, 18 at first complete remission (CR) and 23 at relapse (22 first relapse and 1 second relapse). Whole exome-sequencing was performed on all samples. DNA libraries were prepared with the SureSelect human v5 kit (Agilent) and sequenced on Hiseq1000 (Illumina). The bioinformatic analysis was performed by GECO/integragen using CASAVA variant calling (Illumina) and dedicated pipeline. 18 trios and 5 duos passed the stringent quality control and were analyzed for somatic variants and copy number variations (CNV). Results : After elimination of polymorphisms, the median number of somatic variants corresponding to de novo mutation at diagnosis was 14, while only 3 new somatic variants appeared at relapse (figure 1). Notably, we failed to detect oncogene alterations other than PML/RARA in 7/23 (30%) patients. At diagnostic, 39% of patients (9/23) presented the common FLT3 alterations and at relapse 22% (5/23) of patients presented the known RARA mutations. Moreover, recurrent alterations were observed in activators of the MAPK signaling (22%): NRAS (2 patients), BRAF (1 patient), KRAS (1 patient), SPRY1 (1 patient). Mutations in the NT5C2 gene (3 patients), coding a 5'nucleotidase implicated in resistance to nucleoside-analog therapy, were solely observed at relapse, as in acute lymphoblastic leukemia (ALL). Abnormalities of epigenetic regulators were also detected at diagnostic and/or relapse: WT1 (7 patients, 30%), NSD1 (2 patients), TET2 (1 patient), ASXL1 (1 patient) and MED12 (2 patients). Homozygote WT1 inactivation by mutation plus neutral copy LOH occurred in 3 patients at relapse. The genetic markers identified allowed us to construct several evolution models. In 8 patients (35%), the diagnostic and relapse clones were clearly distinct, supporting the fact that they independently derived from pre-leukemic cells that survived ATRA/chemotherapy. In contrast, other relapses appeared to derive from the diagnostic clone. Conclusion: Our data highlight the genetic simplicity of APL with very few alterations detected and 30% patients without identified mutations in addition to PML/RARa. Our results support the existence of two prototypic mechanisms of relapse: re-emergence of a new APL from persisting pre-leukemic cells and relapse from APLs often expressing strong oncogenes at diagnosis, impeding therapy response and favoring the acquisition of resistance mutations at relapse, including PML/RARA or NT5C2. It will be interesting to assess the prevalence of those two mechanisms in the exceptional cases of relapse in patients treated with more recent frontline regimens that combine ATRA and arsenic in APL. Disclosures Ades: Celgene, Takeda, Novartis, Astex: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Fenaux:Celgene, Janssen,Novartis, Astex, Teva: Honoraria, Research Funding.

scholarly journals Whole-exome sequencing identifies de novo mutation in the COL1A1 gene to underlie the severe osteogenesis imperfecta

2015 ◽  
Vol 9 (1) ◽  
Author(s):  
Katre Maasalu ◽  
Tiit Nikopensius ◽  
Sulev Kõks ◽  
Margit Nõukas ◽  
Mart Kals ◽  
...  
Keyword(s):  
Osteogenesis Imperfecta ◽  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
De Novo ◽  
De Novo Mutation ◽  
Col1a1 Gene ◽  
Whole Exome

scholarly journals Identification of a de novo mutation in KRT5 gene underlying epidermolysis bullosa simplex by whole exome sequencing in a Vietnamese patient

2021 ◽  
Vol 19 (2) ◽  
pp. 223-228
Author(s):  
Ma Thi Huyen Thuong ◽  
Dang Tien Truong ◽  
Nguyen Hai Ha ◽  
Nguyen Dang Ton
Keyword(s):  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Epidermolysis Bullosa ◽  
De Novo ◽  
Recurrence Risk ◽  
Pathogenic Mutation ◽  
De Novo Mutation ◽  
Causative Mutation ◽  
Epidermolysis Bullosa Simplex ◽  
Whole Exome

Epidermolysis bullosa simplex (EBS) is a group of epidermolysis bullosa (EB) and accounts for 75-85% EB cases. Most EBS patients are caused by mutations in KRT5 or KRT14, encoding for keratin 5 and keratin 14, respectively, which impair the structural entirety of paired intermediate filaments expressed in the fracture of basal keratinocytes and subsequent blistering of the epithelium. This study aimed to identify the causative mutation in a Vietnamese EB case. Whole exome sequencing (WES) was performed in the affected individual and revealed a de novo heterozygous pathogenic mutation in exon 7 of KRT5 gene, resulting in an amino acid change at position 477, with glutamic acid to lysine substitution (p.E477K). The KRT5 p.E477K was strong associated with the very severe or lethal of generalized severe EBS (GS-EBS), characterized by the severe symptoms at birth, improving with age and evolution to palmoplantar keratoderma and nail dysplasia. Our finding will aid the molecular diagnosis, prognosis prediction of the patient with GS-EBS due to p.E477K and significant genetic counselling the family concerning the recurrence risk for future pregnancies.

scholarly journals Whole exome sequencing make a definitive diagnosis of a Vietnamese patient with a late onset urea cycle disorder

2020 ◽  
Vol 18 (2) ◽  
pp. 209-221
Author(s):  
Ngoc-Lan Nguyen ◽  
Ngoc Khanh Nguyen ◽  
Chi Dung Vu ◽  
Nguyen Thi Thu Huong ◽  
Nguyen Huy Hoang
Keyword(s):  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Urea Cycle ◽  
De Novo ◽  
Late Onset ◽  
Stop Codon ◽  
Definitive Diagnosis ◽  
De Novo Mutation ◽  
Whole Exome ◽  
Otc Deficiency

            Our report describes a female presenting with vomiting, fever, coma and right hemiplegia at 26 months of age. Biochemical tests revealed hyperammonemia, hyperlactatemia, elevated glutamine level, elevated transaminase and disorder of prothrombin time. She was priory diagnosed with urea cycle disorders (UCDs). UCDs are caused by mutations in eight genes that regulate the synthesis of enzymes and cofactors involved in urea metabolism. Singleton whole exome sequencing was applied to screen causative variants in these genes in the patient at 6 years of age. The result showed one heterozygous stop loss mutation c.1065A>G in the OTC gene as a potential disease causing in the patient. The mutation c.1065A>G leads to alternation of stop codon to tryptophan, resulting in elongation of fourteen amino acids in ornithine transcarbamylase (OTC) protein (p.Ter355TrpextTer14). Sanger sequencing in the family revealed the mutation c.1065A>G was not present in healthy parents and brother. Therefore, this mutation is considered as a de novo mutation in the patient. The mutation c.1065A>G was conferred to pathogenic according to the standards and guidelines of the American College of Medical Genetics and Genomics and the Association for Molecular Pathology with 1 strong (PS2), 3 moderate (PM2, PM4 and PM5) and 1 support criteria (PP2). Although OTC deficiency is an X-linked recessive inheritance, approximately 15% of females carrying heterozygous variants showed the late onset OTC deficiency. Therefore, in combination of clinical presentations, laboratory findings and molecular genetic analyses, we made a definitive diagnosis of the patient with late onset OTC deficiency, a disorder of UCDs.

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