scholarly journals The spectrum of ATM gene mutations in Iranian patients with ataxia-telangiectasia

2020 ◽  
Author(s):  
Parisa Amirifar ◽  
Mohammad Reza Ranjouri ◽  
salar Pashangzadeh ◽  
Martin Lavin ◽  
Reza Yazdani ◽  
...  
Keyword(s):  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Ataxia Telangiectasia ◽  
Genetic Disorder ◽  
Clinical Manifestations ◽  
Gene Mutations ◽  
Public Health Care ◽  
Severe Phenotype ◽  
Whole Exome ◽  
Age Of Diagnosis

Abstract Background: Ataxia-telangiectasia (A-T) is a rare genetic disorder characterized by a distinct range of clinical manifestations, including progressive ataxia, immunodeficiency, and radiosensitivity. Methods: Clinical data, laboratory results, and genetic data were collected from forty-three A-T patients. Whole exome sequencing and Sanger sequencing were done for the patients clinically diagnosed as suffering from A-T. Based on the phenotype severity of the disease, patients were divided into severe and mild sub-groups. Results: The median (IQR) age of diagnosis in this cohort was 5 (3-7) years and various types of clinical manifestations, including fever (p= 0.005), lower respiratory tract infection (p= 0.033), diarrhea (p= 0.014), and hepatosplenomegaly (p= 0.032) were significantly higher amongst patients diagnosed with the severe phenotype. Our results showed a strong correlation between phenotype severity and mutation type. The chance of having severe phenotype in patients who have severe mutations, including frameshift and nonsense, was 7.3 times higher compared to patients who were categorized in the mild genotype group (odds ratio= 7.3, p= 0.006). Thirty-four types of mutations including 9 novel mutations, were observed in our study. Conclusion: Molecular analysis provides the opportunity for accurate diagnosis and timely management in A-T patients with chronic progressive disease, especially infections and the risk of malignancies. This study characterizes for the first time, the broad spectrum of mutations and phenotypes in Iranian A-T patients which are required for carrier detection and reducing the burden of disease in future using the patients’ families and for the public health care system. Keywords: Ataxia-telangiectasia (A-T), ATM, Whole-exome sequencing, Class switching recombination (CSR), phenotype severity.

scholarly journals Case Report: Whole-Exome Sequencing With MLPA Revealed Variants in Two Genes in a Patient With Combined Manifestations of Spinal Muscular Atrophy and Duchenne Muscular Dystrophy

2021 ◽  
Vol 12 ◽  
Author(s):  
Yu Xia ◽  
Yijie Feng ◽  
Lu Xu ◽  
Xiaoyang Chen ◽  
Feng Gao ◽  
...  
Keyword(s):  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Spinal Muscular Atrophy ◽  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Muscular Atrophy ◽  
Genetic Disorder ◽  
Clinical Manifestations ◽  
Chinese Family ◽  
Whole Exome

Spinal muscular atrophy (SMA) and Duchenne muscular dystrophy (DMD) are two common kinds of neuromuscular disorders sharing various similarities in clinical manifestations. SMA is an autosomal recessive genetic disorder that results from biallelic mutations of the survival motor neuron 1 gene (SMN1; OMIM 600354) on the 5q13 chromosome. DMD is an X-linked disorder caused by defects in the DMD gene (OMIM 300377) on the X chromosome. Here, for the first time, we report a case from a Chinese family who present with clinical manifestations of both two diseases, including poor motor development and progressive muscle weakness. We identified a homozygous deletion in exons 7 and 8 of the SMN1 gene and a deletion in exon 50 of the DMD gene by whole-exome sequencing (WES) and multiplex ligation-dependent probe amplification (MLPA). This case expands our understanding of diagnosis for synchronous SMA and DMD and highlights the importance of various genetic testing methods, including WES, in differential diagnosis of neuromuscular diseases.

scholarly journals Facial cleft? The first case of manitoba‐oculo‐tricho‐anal syndrome with novel mutations in China: a case report

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Shuchen Gu ◽  
Yimin Khoong ◽  
Xin Huang ◽  
Tao Zan
Keyword(s):  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Clinical Manifestations ◽  
Sporadic Case ◽  
Facial Cleft ◽  
Ocular Manifestations ◽  
First Case ◽  
Whole Exome ◽  
Chinese Girl ◽  
Low Prevalence

Abstract Background Manitoba-oculo-tricho-anal (MOTA) syndrome is a rare syndrome with only 27 cases reported worldwide so far, but none was reported in the population of Eastern Asia. Such extremely low prevalence might be contributed by misdiagnosis due to its similarities in ocular manifestations with facial cleft. In our study, we discovered the first case of MOTA syndrome in the population of China, with 2 novel FRAS1 related extracellular matrix 1 (FREM1) gene stop-gain mutations confirmed by whole exome sequencing. Case presentation A 12-year-old Chinese girl presented with facial cleft-like deformities including aberrant hairline, blepharon-coloboma and broad bifid nose since birth. Whole exome sequencing resulted in the identification of 2 novel stop-gain mutations in the FREM1 gene. Diagnosis of MOTA syndrome was then established. Conclusions We discovered the first sporadic case of MOTA syndrome according to clinical manifestations and genetic etiology in the Chinese population. We have identified 2 novel stop-gain mutations in FREM1 gene which further expands the spectrum of mutational seen in the MOTA syndrome. Further research should be conducted for better understanding of its mechanism, establishment of an accurate diagnosis, and eventually the exploitation of a more effective and comprehensive therapeutic intervention for MOTA syndrome.

scholarly journals The identification of novel gene mutations for degenerative lumbar spinal stenosis using whole-exome sequencing in a Chinese cohort

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Xin Jiang ◽  
Dong Chen
Keyword(s):  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Spinal Stenosis ◽  
Lumbar Spinal Stenosis ◽  
Gene Mutations ◽  
Specific Gene ◽  
Single Nucleotide ◽  
Degenerative Lumbar Spinal Stenosis ◽  
Whole Exome ◽  
Lumbar Spinal

Abstract Background Degenerative lumbar spinal stenosis (DLSS) is a common lumbar disease that requires surgery. Previous studies have indicated that genetic mutations are implicated in DLSS. However, studies on specific gene mutations are scarce. Whole-exome sequencing (WES) is a valuable research tool that identifies disease-causing genes and could become an effective strategy to investigate DLSS pathogenesis. Methods From January 2016 to December 2017, we recruited 50 unrelated patients with symptoms consistent with DLSS and 25 unrelated healthy controls. We conducted WES and exome data analysis to identify susceptible genes. Allele mutations firstly identified potential DLSS variants in controls to the patients’ group. We conducted a site-based association analysis to identify pathogenic variants using PolyPhen2, SIFT, Mutation Taster, Combined Annotation Dependent Depletion, and Phenolyzer algorithms. Potential variants were further confirmed using manual curation and validated using Sanger sequencing. Results In this cohort, the major classification variant was missense_mutation, the major variant type was single nucleotide polymorphism (SNP), and the major single nucleotide variation was C > T. Multiple SNPs in 34 genes were identified when filtered allele mutations in controls to retain only patient mutations. Pathway enrichment analyses revealed that mutated genes were mainly enriched for immune response-related signaling pathways. Using the Novegene database, site-based associations revealed several novel variants, including HLA-DRB1, PARK2, ACTR8, AOAH, BCORL1, MKRN2, NRG4, NUP205 genes, etc., were DLSS related. Conclusions Our study revealed that deleterious mutations in several genes might contribute to DLSS etiology. By screening and confirming susceptibility genes using WES, we provided more information on disease pathogenesis. Further WES studies incorporating larger DLSS patient cohorts are required to comprehend the genetic landscape of DLSS pathophysiology fully.

scholarly journals Whole-exome sequencing associates novel CSMD1 gene mutations with familial Parkinson disease

2017 ◽  
Vol 3 (5) ◽  
pp. e177 ◽  
Author(s):  
Javier Ruiz-Martínez ◽  
Luis J. Azcona ◽  
Alberto Bergareche ◽  
Jose F. Martí-Massó ◽  
Coro Paisán-Ruiz
Keyword(s):  
Parkinson Disease ◽  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Genome Wide Association Study ◽  
Single Gene ◽  
Gene Mutations ◽  
Complement Control Protein ◽  
Genome Wide ◽  
Whole Exome ◽  
A Genome

Objective:Despite the enormous advancements made in deciphering the genetic architecture of Parkinson disease (PD), the majority of PD is idiopathic, with single gene mutations explaining only a small proportion of the cases.Methods:In this study, we clinically evaluated 2 unrelated Spanish families diagnosed with PD, in which known PD genes were previously excluded, and performed whole-exome sequencing analyses in affected individuals for disease gene identification.Results:Patients were diagnosed with typical PD without relevant distinctive symptoms. Two different novel mutations were identified in the CSMD1 gene. The CSMD1 gene, which encodes a complement control protein that is known to participate in the complement activation and inflammation in the developing CNS, was previously shown to be associated with the risk of PD in a genome-wide association study.Conclusions:We conclude that the CSMD1 mutations identified in this study might be responsible for the PD phenotype observed in our examined patients. This, along with previous reported studies, may suggest the complement pathway as an important therapeutic target for PD and other neurodegenerative diseases.

scholarly journals Case report: targeted whole exome sequencing enables the first prenatal diagnosis of the lethal skeletal dysplasia Osteocraniostenosis

2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Lara Pemberton ◽  
Robert Barker ◽  
Anna Cockell ◽  
Vijaya Ramachandran ◽  
Andrea Haworth ◽  
...  
Keyword(s):  
Case Report ◽  
Prenatal Diagnosis ◽  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Skeletal Dysplasia ◽  
Genetic Disorder ◽  
Specific Gene ◽  
Ultrasound Images ◽  
Whole Exome ◽  
Lethal Skeletal Dysplasia

Abstract Background Osteocraniostenosis (OCS) is a rare genetic disorder characterised by premature closure of cranial sutures, gracile bones and perinatal lethality. Previously, diagnosis has only been possible postnatally on clinical and radiological features. This study describes the first prenatal diagnosis of OCS. Case presentation In this case prenatal ultrasound images were suggestive of a serious but non-lethal skeletal dysplasia. Due to the uncertain prognosis the parents were offered Whole Exome Sequencing (WES), which identified a specific gene mutation in the FAMIIIa gene. This mutation had previously been detected in two cases and was lethal in both perinatally. This established the diagnosis, a clear prognosis and allowed informed parental choice regarding ongoing pregnancy management. Conclusions This case report supports the use of targeted WES prenatally to confirm the underlying cause and prognosis of sonographically suspected abnormalities.

Whole Exome Sequencing Reveals Spectrum of Gene Mutations in Pediatric AML

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 124-124
Author(s):  
Norio Shiba ◽  
Kenichi Yoshida ◽  
Yusuke Okuno ◽  
Yuichi Shiraishi ◽  
Yasunobu Nagata ◽  
...  
Keyword(s):  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Conflicts Of Interest ◽  
Massively Parallel Sequencing ◽  
Gene Mutations ◽  
Pediatric Leukemia ◽  
Protein Coding ◽  
Whole Exome ◽  
Recurrent Mutations ◽  
Pediatric Aml

Abstract Abstract 124 Background Pediatric acute myeloid leukemia (AML) comprises ∼20% of pediatric leukemia, representing one of the major therapeutic challenges in pediatric oncology with the current overall survival remains to be ∼60%. As for the molecular pathogenesis of pediatric AML, it has been well established that gene fusions generated by recurrent chromosomal translocations, including t(15;17), t(8;21), inv(16) and t(9;11), play critical roles in leukemogenesis. However, they are not sufficient for leukemogenesis, indicating apparent need of additional genetic hits, and approximately 20% of pediatric AML cases lack any detectable chromosomal abnormalities (normal karyotype AML). Currently, a number of gene mutations have been implicated in the pathogenesis of both adult and pediatric AML, including mutations of RAS, KIT and FLT3, and more recently, a new class of mutational targets have been reported in adult AML, including CEBPA, NPM1, DNMT3A, IDH1/2, TET2 and EZH2. However, mutations of the latter class of gene targets seem to be rare in pediatric AML cases, whereas other abnormalities such as a NUP98-NSD1 fusion are barely found in adult cases, indicating the discrete pathogenesis between both AML at least in their subsets. Meanwhile, the recent development of massively parallel sequencing technologies has provided a new opportunity to discover genetic changes across the entire genomes or protein-coding sequences in human cancers at a single-nucleotide level, which could be successfully applied to the genetic analysis of pediatric AML to obtain a better understanding of its pathogenesis. Methods In order to reveal a complete registry of gene mutations and other genetic lesions, we performed whole exome sequencing of paired tumor-normal specimens from 23 pediatric AML cases using Illumina HiSeq 2000. Although incapable of detecting non-coding mutations and gene rearrangements, the whole-exome approach is a well-established strategy for obtaining comprehensive spectrum of protein-coding mutations. Recurrently mutated genes were further examined for mutations in an extended cohort of 200 pediatric AML samples, using deep sequencing, in which the prevalence and relative allele frequencies of mutations were investigated. Results Whole-exome sequencing of paired tumor-normal DNA from 23 patients were analyzed with a mean coverage of more than x120, and 90 % of the target sequences were analyzed at more than x20 depth on average. A total of 237 somatic mutations or 10.3 mutations per sample were identified. Many of the recurrent mutations identified in this study involved previously reported targets in adult AML, such as FLT3, CEBPA, KIT, CBL, NRAS, WT1, MLL3, BCOR, BCORL1, EZH2, and major cohesin components including XXX and ZZZ. On the other hand, several genes were newly identified in the current study, including BRAF, CUL2 and COL4A5, which were validated for the clinical significance in an extended cohort of 200 pediatric cases. Discussion Whole exome sequencing unmasked a complexity of gene mutations in pediatric AML genomes. Our results indicated that a subset of pediatric AML represents a discrete entity that could be discriminated from the adult counterpart, in terms of the spectrum of gene mutations. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Phenotypic Heterogeneity and Genotypic Spectrum of Primary Immunodeficiencies with Whole Exome Sequencing in a Thai Patient Cohort

2021 ◽  
Author(s):  
Maliwan Tengsujaritkul ◽  
Narissara Suratannon ◽  
Chupong Ittiwut ◽  
Rungnapa Ittiwut ◽  
Pantipa Chatchatee ◽  
...  
Keyword(s):  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Clinical Decision Making ◽  
Diagnostic Yield ◽  
Disease Onset ◽  
Clinical Manifestations ◽  
Genetic Defects ◽  
Diagnostic Strategy ◽  
Patient Cohort ◽  
Whole Exome

Background: Primary immunodeficiency diseases (PIDs) comprise more than 400 rare diseases with potential life-threatening conditions. Clinical manifestations and genetic defects are heterogeneous and diverse among populations. Here, we aimed to characterize the clinical, immunological and genetic features of Thai pediatric patients with PIDs. The use of whole exome sequencing (WES) in diagnosis and clinical decision making was also assessed. Methods: 36 unrelated patients with clinical and laboratory findings consistent with PIDs were recruited from January 2010 to December 2020. WES was performed to identify the underlying genetic defects. Results: The median age of disease onset was 4 months (range; 1 month to 13 years) and 24 were male (66.7%). Recurrent sinopulmonary tract infection was the most common clinical presentation followed by septicemia, and severe pneumonia. Using WES, we successfully identified the underlying genetic defects in 18 patients (50%). Of the 20 variants identified, six have not been previously described (30%). According to the International Union of Immunological Societies (IUIS), 38.9% of these detected cases (7/18) were found to harbor variants associated with genes in combined immunodeficiencies with associated or syndromic features (Class II). Conclusion: The diagnostic yield of WES in this patient cohort was 50%. Six novel genetic variants in PID genes were identified. The clinical usefulness of WES in PIDs was demonstrated, emphasizing it as an effective diagnostic strategy in these genetically heterogeneous disorders.

scholarly journals Diagnostic utility of exome sequencing for inherited peripheral neuropathies

2020 ◽  
Vol 10 (4) ◽  
pp. 12-26
Author(s):  
O. A. Shchagina ◽  
O. P. Ryzhkova ◽  
A. L. Chukhrova ◽  
T. V. Milovidova ◽  
P. Gundorova ◽  
...  
Keyword(s):  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Neuromuscular Disorders ◽  
Congenital Muscular Dystrophy ◽  
Gene Mutations ◽  
Research Centre ◽  
Congenital Myasthenic Syndrome ◽  
Hereditary Motor ◽  
Pathogenic Variants ◽  
Whole Exome

Introduction. Hereditary motor and sensory neuropathies, a highly genetic heterogeneous group of disorders, have a phenotype caused by peripheral nerve damage.Purpose of the study – to assess the extent of genetic heterogeneity of hereditary motor and sensory neuropathies in Russian patients and to evaluate the diagnostic effectiveness of using full-exome research methods to find the genetic cause of hereditary motor and sensory neuropathies.Materials and methods. The material for the study was DNA samples from 51 patients and their family members referred for whole exome sequencing to the DNA-diagnostics laboratory of Research Centre for Medical Genetics in 2017–2019. Methods: whole exome sequencing, Sanger sequencing, restriction fragment length polymorphism.Results. Whole exome sequencing in combination with segregation analysis of the pathogenic variants in families allowed to determine the cause of the disease in 41 % of cases. In another 16 % of cases, candidate genetic variants as a possible cause of the disease were revealed, but additional studies are needed to confirm it. The most frequently mutated gene was MFN2 caused neuropathy in 6 unrelated families. MPZ gene mutations were detected in two families, AARS gene mutations were revealed in another two families, and mutations in GJB1, HINT1, INF2, LRSAM1, LITAF, MME, NEFL, WWOX were detected once. Among the causal variants, mutations in B4GALNT1 caused spastic paraplegia, in COL6A1 led to Bethlem’s congenital muscular dystrophy, and in SYT2 caused congenital myasthenic syndrome indicating difficulties in differential diagnosis of inherited neuromuscular disorders. A PMP22 duplication was detected in 2 families prior to whole exome sequencing.Conclusion. Whole exome sequencing is very important for finding the molecular cause of hereditary motor and sensory neuropathies. In most cases, additional methods should be used to clarify the pathogenicity of variants detected by whole exome sequencing. However, it is necessary to remember that the most common cause of the disease is a large duplication of the region 17p11.2.

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