scholarly journals A Chinese Patient with Spastic Paraplegia Type 4 with a De Novo Mutation in the SPAST Gene

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Li Xu ◽  
Zijuan Peng ◽  
Chunhui Zhou ◽  
Jiqing Wang ◽  
Hunjin Luo ◽  
...  
Keyword(s):  
Missense Mutation ◽  
De Novo ◽  
Chinese Patient ◽  
Chinese Woman ◽  
De Novo Mutation ◽  
Spastic Paraplegia ◽  
Gene Segregation ◽  
Whole Exome ◽  
The Family ◽  
Family Gene

Background. Spastic paraplegia type 4 (SPG4) is the most common type of hereditary spastic paraplegia (HSP) caused by mutations in the SPAST gene. Case Presentation. We report the case of a 27-year-old pregnant Chinese woman with HSP in whom we identified a missense mutation in the SPAST gene (c.1496G>A, p.Arg499His) and a nonsense mutation in the NEFH gene (c.289G>T, p.Glu97 ∗ ) via whole-exome sequencing; this finding corroborated that of Sanger sequencing. The patient exhibited the pure SPG4 phenotype with onset during childhood. The SPAST mutation was absent in the parents and paternal relatives. However, the NEFH mutation was identified in five people with no clinical phenotype. Based on theoretical conjecture and the family gene segregation information, we concluded that the SPAST mutation, but not the NEFH mutation, accounted for the proband’s phenotype. Eventually, the woman gave birth to a healthy baby girl with the NEFH mutation. Conclusion. In this report, we identified a missense mutation in the SPAST gene (p.Arg499His) in a 27-year-old pregnant Chinese woman with HSP. We believe that this study expands the knowledge about the clinical parameters and mutation spectrum of SPG4.

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.

scholarly journals Analysis of De Novo Mutations in Sporadic Cardiomyopathies Emphasizes Their Clinical Relevance and Points to Novel Candidate Genes

2020 ◽  
Vol 9 (2) ◽  
pp. 370 ◽  
Author(s):  
Maria Franaszczyk ◽  
Grazyna Truszkowska ◽  
Przemyslaw Chmielewski ◽  
Malgorzata Rydzanicz ◽  
Joanna Kosinska ◽  
...  
Keyword(s):  
Candidate Genes ◽  
De Novo ◽  
Positive Family History ◽  
Disease Onset ◽  
De Novo Mutation ◽  
De Novo Mutations ◽  
Whole Exome ◽  
The Family ◽  
High Prevalence ◽  
Generation Sequencing

The vast majority of cardiomyopathies have an autosomal dominant inheritance; hence, genetic testing is typically offered to patients with a positive family history. A de novo mutation is a new germline mutation not inherited from either parent. The purpose of our study was to search for de novo mutations in patients with cardiomyopathy and no evidence of the disease in the family. Using next-generation sequencing, we analyzed cardiomyopathy genes in 12 probands. In 8 (66.7%), we found de novo variants in known cardiomyopathy genes (TTN, DSP, SCN5A, TNNC1, TPM1, CRYAB, MYH7). In the remaining probands, the analysis was extended to whole exome sequencing in a trio (proband and parents). We found de novo variants in genes that, so far, were not associated with any disease (TRIB3, SLC2A6), a possible disease-causing biallelic genotype (APOBEC gene family), and a de novo mosaic variant without strong evidence of pathogenicity (UNC45A). The high prevalence of de novo mutations emphasizes that genetic screening is also indicated in cases of sporadic cardiomyopathy. Moreover, we have identified novel cardiomyopathy candidate genes that are likely to affect immunological function and/or reaction to stress that could be especially relevant in patients with disease onset associated with infection/infestation.

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.

scholarly journals A de novo variant in CASK gene causing intellectual disability and brain hypoplasia: A Case Report and Literature Review

2021 ◽  
Author(s):  
Ying Zhang ◽  
Yanyan Nie ◽  
Yu Mu ◽  
Jie Zheng ◽  
Xiaowei Xu ◽  
...  
Keyword(s):  
Intellectual Disability ◽  
Mental Disorders ◽  
De Novo ◽  
Clinical Symptoms ◽  
Clinical Manifestations ◽  
De Novo Mutation ◽  
Loss Of Function ◽  
Bioinformatics Analyses ◽  
Whole Exome ◽  
De Novo Variant

Abstract Background：The pathogenic variation of CASK gene can cause CASK related mental disorders. The main clinical manifestations are microcephaly with pontine and cerebellar hypoplasia, X-linked mental disorders with or without nystagmus and FG syndrome. The main pathogenic mechanism is the loss of function of related protein caused by mutation. We reported a Chinese male newborn with a de novo variant in CASK gene. Case presentation：We present an 18-day-old baby with intellectual disability and brain hypoplasia. Whole-exome sequencing was performed, which detected a hemizygous missense mutation c.764G>A of CASK gene. The mutation changed the 255th amino acid from Arg to His. Software based bioinformatics analyses were conducted to infer its functional effect.Conclusions：In this paper, a de novo mutation of CASK gene was reported. Moreover, a detailed description of all the cases described in the literature is reported.CASK mutations cause a variety of clinical phenotypes. Its diagnosis is difficult due to the lack of typical clinical symptoms. Genetic testing should be performed as early as possible if this disease is suspected. This case provides an important reference for the diagnosis and treatment of future cases.

scholarly journals De novo REEP2 missense mutation in pure hereditary spastic paraplegia

2017 ◽  
Vol 4 (5) ◽  
pp. 347-350 ◽  
Author(s):  
Ricardo H. Roda ◽  
Alice B. Schindler ◽  
Craig Blackstone
Keyword(s):  
Missense Mutation ◽  
Hereditary Spastic Paraplegia ◽  
De Novo ◽  
Spastic Paraplegia

A De Novo Mutation of STK11 Gene in a Chinese Patient with Peutz–Jeghers Syndrome

2009 ◽  
Vol 55 (4) ◽  
pp. 1032-1036 ◽  
Author(s):  
Ying Gao ◽  
Fa-Ming Zhang ◽  
Shu Huang ◽  
Xiang Wang ◽  
Ping Zhang ◽  
...  
Keyword(s):  
De Novo ◽  
Chinese Patient ◽  
De Novo Mutation ◽  
Stk11 Gene ◽  
Peutz Jeghers Syndrome

scholarly journals Case Report: A Novel De Novo Missense Mutation of the GRIA2 Gene in a Chinese Case of Neurodevelopmental Disorder With Language Impairment

2021 ◽  
Vol 12 ◽  
Author(s):  
Bingbo Zhou ◽  
Chuan Zhang ◽  
Lei Zheng ◽  
Zhiqiang Wang ◽  
Xue Chen ◽  
...  
Keyword(s):  
Exome Sequencing ◽  
Missense Mutation ◽  
Developmental Delay ◽  
Whole Exome Sequencing ◽  
Language Impairment ◽  
De Novo ◽  
Neurodevelopmental Disorder ◽  
Behavioral Abnormalities ◽  
Whole Exome ◽  
Chinese Case

Introduction: Neurodevelopmental disorders with language impairment and behavioral abnormalities (NEDLIB) are a disease caused by heterozygous variants in the glutamate ionotropic receptor AMPA type subunit 2 (GRIA2) gene, which manifest as impaired mental development or developmental delay, behavioral abnormalities including autistic characteristics, and language disorders. Currently, only a few mutations in the GRIA2 gene have been discovered.Methods: A GRIA2 variation was detected in a patient by whole-exome sequencing, and the site was validated by Sanger sequencing from the family.Results: We report a Chinese case of NEDLIB in a girl with language impairment and developmental delay through whole-exome sequencing (WES). Genetic analysis showed that there was a de novo missense mutation, c.1934T > G (p.Leu645Arg), in the GRIA2 gene (NM_001083619.1), which has never been reported before.Conclusion: Our case shows the potential diagnostic role of WES in NEDLIB, expands the GRIA2 gene mutation spectrum, and further deepens the understanding of NEDLIB. Deepening the study of the genetic and clinical heterogeneity, treatment, and prognosis of the disease is still our future challenge and focus.

scholarly journals Leukoencephalopathia, demyelinating peripheral neuropathy and dural ectasia explained by a not formerly described de novo mutation in the SAMD9L gene, ends 27 years of investigations – A case report

2019 ◽  
Author(s):  
Sofia Thunström ◽  
Markus Axelsson
Keyword(s):  
Case Report ◽  
Peripheral Neuropathy ◽  
De Novo ◽  
Age Of Onset ◽  
De Novo Mutation ◽  
Missense Mutations ◽  
Dural Ectasia ◽  
Whole Exome ◽  
Demyelinating Peripheral Neuropathy ◽  
Multiple Cysts

Abstract Background: Missense mutations in SAMD9L gene is associated with ataxia-pancytopenia syndrome (ATXPC), OMIM#159550. Common clinical features in these patients include neurological and hematological symptoms. The phenotype and age of onset is variable. Case Presentation: In this case report whole exome sequencing (WES) revealed a not previously reported de novo variant c.2686T>G, p.(Phe896Val) in SAMD9L in a patient with widespread findings of slow developing pathology in the peripheral and central nervous system. The clinical picture was dominated by neurological symptoms, unlike previously described cases, and in addition dural ectasias and multiple cysts in the brain was observed using magnetic resonance imaging. Conclusions: This case underscores the effect of variable expressivity, i.e. different mutations in the same gene can cause different phenotypes. Keywords: Leukoencephalopathia, demyelinating peripheral neuropathy, dural ectasia explained, de novo mutation, the SAMD9L gene.

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 Gain-of-function IKBKB mutation causes human combined immune deficiency

2018 ◽  
Vol 215 (11) ◽  
pp. 2715-2724 ◽  
Author(s):  
Chelisa Cardinez ◽  
Bahar Miraghazadeh ◽  
Kay Tanita ◽  
Elizabeth da Silva ◽  
Akihiro Hoshino ◽  
...  
Keyword(s):  
B Cell ◽  
Missense Mutation ◽  
De Novo ◽  
Genetic Mutations ◽  
Whole Exome ◽  
Immune Deficiencies ◽  
Codon Change ◽  
B Cell Deficiency ◽  
Conserved Residue ◽  
Insight Into

Genetic mutations account for many devastating early onset immune deficiencies. In contrast, less severe and later onset immune diseases, including in patients with no prior family history, remain poorly understood. Whole exome sequencing in two cohorts of such patients identified a novel heterozygous de novo IKBKB missense mutation (c.607G>A) in two separate kindreds in whom probands presented with immune dysregulation, combined T and B cell deficiency, inflammation, and epithelial defects. IKBKB encodes IKK2, which activates NF-κB signaling. IKK2V203I results in enhanced NF-κB signaling, as well as T and B cell functional defects. IKK2V203 is a highly conserved residue, and to prove causation, we generated an accurate mouse model by introducing the precise orthologous codon change in Ikbkb using CRISPR/Cas9. Mice and humans carrying this missense mutation exhibit remarkably similar cellular and biochemical phenotypes. Accurate mouse models engineered by CRISPR/Cas9 can help characterize novel syndromes arising from de novo germline mutations and yield insight into pathogenesis.

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