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Dravet syndrome is a severe form of epilepsy characterised by recurrent seizures and cognitive impairment. It is mainly caused by variant in the SCN1A gene in 90% of cases, which codes for the α subunit of the voltage-gated sodium channel. In this study, we present one suspected case of Dravet syndrome in Moroccan child that underwent exome analysis and were confirmed by Sanger sequencing. The variant was identified in the SCN1A gene, and is a new variant that has never been described in the literature. The variant was found de nova in our case, indicating that it was not inherited from the parents. The variant, SCN1A c.965-2A>G p.(?), is located at the splice site and results in an unknown modification of the protein. This variant is considered pathogenic on the basis of previous studies. These results contribute to our knowledge of the SCN1A gene mutations associated with Dravet syndrome and underline the importance of genetic analysis in the diagnosis and confirmation of this disorder. Further studies are needed to better understand the functional consequences of this variant and its implications for therapeutic strategies in Dravet syndrome.
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Epilepsias Mioclónicas , Epilepsia , Niño , Humanos , Epilepsias Mioclónicas/genética , Epilepsias Mioclónicas/diagnóstico , Canal de Sodio Activado por Voltaje NAV1.1/genética , Epilepsia/genética , Mutación/genética , Análisis de Secuencia , ConvulsionesRESUMEN
Introduction: Colorectal cancers are the world's third most commonly diagnosed type of cancer. Currently, there are several diagnostic and treatment options to combat it. However, a delay in detection of the disease is life-threatening. Additionally, a thorough analysis of the exomes of cancers reveals potential variation data that can be used for early disease prognosis. Methods: By utilizing a comprehensive computational investigation, the present study aimed to reveal mutations that could potentially predispose to colorectal cancer. Ten colorectal cancer exomes were retrieved. Quality control assessments were performed using FastQC and MultiQC, gapped alignment to the human reference genome (hg19) using Bowtie2 and calling the germline variants using Haplotype caller in the GATK pipeline. The variants were filtered and annotated using SIFT and PolyPhen2 successfully categorized the mutations into synonymous, non-synonymous, start loss and stop gain mutations as well as marked them as possibly damaging, probably damaging and benign. This mutational profile helped in shortlisting frequently occurring mutations and associated genes, for which the downstream multi-dimensional expression analyses were carried out. Results: Our work involved prioritizing the non-synonymous, deleterious SNPs since these polymorphisms bring about a functional alteration to the phenotype. The top variations associated with their genes with the highest frequency of occurrence included LGALS8, CTSB, RAD17, CPNE1, OPRM1, SEMA4D, MUC4, PDE4DIP, ELN and ADRA1A. An in-depth multi-dimensional downstream analysis of all these genes in terms of gene expression profiling and analysis and differential gene expression with regard to various cancer types revealed CTSB and CPNE1 as highly expressed and overregulated genes in colorectal cancer. Conclusion: Our work provides insights into the various alterations that might possibly lead to colorectal cancer and suggests the possibility of utilizing the most important genes identified for wet-lab experimentation.
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Histiocytic sarcoma (HS) is a rare aggressive hematological malignancy reported to occur secondary to B cell lymphoma. We report a case of HS secondary to splenic marginal zone lymphoma (SMZL) complicated by autoimmune hemolytic anemia (AIHA) in a 64-year-old man. He was referred to our department with anemia and was diagnosed as having AIHA. After starting treatment with prednisolone, atypical lymphocytes appeared in his blood tests, and a bone marrow biopsy revealed invasion by B cell lymphoma. A CT scan showed splenomegaly and a pancreatic mass, which confirmed the diagnosis of SMZL. The patient received bendamustine and rituximab as chemotherapy, which rapidly improved the anemia and splenomegaly and reduced atypical lymphocytes. However, left lumbar back pain appeared along with an increase in the pancreatic mass, and he died suddenly of acute renal failure. An autopsy revealed that the tumor had invaded several organs including the pancreas, and immunohistochemistry was positive for CD163, leading to the diagnosis of HS. Furthermore, the specimens of SMZL and HS were positive for IgH gene reconstitution, and exome analysis showed genetic abnormalities in 226 genes including CARD11, suggesting that the SMZL and HS had the same origin.
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Sarcoma Histiocítico , Linfoma de Células B de la Zona Marginal , Neoplasias del Bazo , Humanos , Masculino , Persona de Mediana Edad , Neoplasias del Bazo/genética , Neoplasias del Bazo/patología , Neoplasias del Bazo/diagnóstico , Linfoma de Células B de la Zona Marginal/genética , Linfoma de Células B de la Zona Marginal/patología , Linfoma de Células B de la Zona Marginal/diagnóstico , Linfoma de Células B de la Zona Marginal/tratamiento farmacológico , Sarcoma Histiocítico/patología , Sarcoma Histiocítico/genética , Sarcoma Histiocítico/diagnóstico , Secuenciación del Exoma , Resultado FatalRESUMEN
BACKGROUND: Non-small cell lung cancer is a very poor prognosis disease. Molecular analyses have highlighted several genetic alterations which may be targeted by specific therapies. In clinical practice, progression-free survival on EGFR TKI treatment is between 12 and 14 months. However, some patients progress rapidly in less than 6 months, while others remain free of progression for 16 months or even longer during EGFR TKI treatment. METHODS: We sequenced tumor exomes from 135 lung cancer patients (79 with EGFR-wildtype (WT), 56 with EGFR-mutant tumors) enrolled in the ALCAPONE trial (genomic analysis of lung cancers by next generation sequencing for personalized treatment). RESULTS: Some germline polymorphisms were enriched in the EGFR-mutant subset compared to EGFR-WT tumors or to a reference population. However, the most interesting observation was the negative impact of some germline SNPs in immunity-related genes on survival on EGFR TKI treatment. Indeed, the presence of one of three particular SNPs in the HLA-DRB5 gene was associated with a decreased PFS on EGFR TKI. Moreover, some SNPs in the KIR3DL1 and KIR3DL2 genes were linked to a decrease in both progression-free and overall survival of patients with EGFR-mutant tumors. CONCLUSION: Our data suggest that SNPs in genes expressed by immune cells may influence the response to targeted treatments, such as EGFR TKIs. This indicates that the impact of these cells may not be limited to modulating the response to immunotherapies. Further studies are needed to determine the exact mechanisms underlying this influence and to identify the associated predictive and prognostic markers that would allow to refine treatments and so improve lung cancer patient outcomes. TRIAL REGISTRATION: NCT02281214: NGS Genome Analysis in Personalization of Lung Cancer Treatment (ALCAPONE).
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Carcinoma de Pulmón de Células no Pequeñas , Carcinoma , Neoplasias Pulmonares , Humanos , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/genética , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/genética , Células Germinativas , Pulmón , Receptores ErbB/genéticaRESUMEN
Variant prioritization is a crucial step in the analysis of exome and genome sequencing. Multiple phenotype-driven tools have been developed to automate the variant prioritization process, but the efficacy of these tools in clinical setting with fuzzy phenotypic information and whether ensemble of these tools could outperform single algorithm remains to be assessed. A large rare disease cohort with heterogeneous phenotypic information, including a primary cohort of 1614 patients and a replication cohort of 1904 patients referred to exome sequencing, were recruited to assess the efficacy of variant prioritization and their ensemble. Three freely available tools-Exomiser, Xrare, and DeepPVP-and their ensemble were evaluated. The performance of all three tools was influenced by the attributes of phenotypic input. When combining these three tools by weighted-sum entropy method (EWE3), the ensemble outperformed any single algorithm, achieving a rate of 78% diagnostic variants in top 3 (13% improvement over current best performer, compared to Exomiser: 63%, Xrare: 65%, and DeepPVP: 51%), 88% in top 10 and 96% in top 30. The results were replicated in another independent cohort. Our study supports using entropy-weighted ensemble of multiple tools to improve variant prioritization and accelerate molecular diagnosis in exome/genome sequencing.
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Algoritmos , Exoma , Humanos , Exoma/genética , Entropía , Fenotipo , Enfermedades Raras/genética , Programas InformáticosRESUMEN
Cantù syndrome (CS) is a rare multisystemic disorder, characterized by congenital hypertrichosis, macrocephaly, facial dysmorphisms, cardiomegaly, vascular, and skeletal anomalies. From the cognitive point of view, most of the patients show a mild speech delay and a few of them present intellectual disability and learning difficulties. To date, most CS-reported cases are caused by heterozygous ABCC9 gene mutations. Only three patients with CS and heterozygous KCNJ8 gene variants have been reported. The authors here present the fourth case of CS with a variant in KCNJ8 in a 6-month-old baby. Diagnosis was reached through Trio-Whole Exome analysis that revealed a de novo missense variant in KCNJ8.
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Hipertricosis , Osteocondrodisplasias , Cardiomegalia/genética , Humanos , Hipertricosis/diagnóstico , Hipertricosis/genética , Lactante , Mutación Missense/genética , Osteocondrodisplasias/genéticaRESUMEN
Lateral meningocele syndrome is characterized by multiple lateral meningoceles with a distinctive craniofacial appearance, hyperextensibility of the skin, and hypermobility of the joints. The syndrome is caused by heterozygous truncating variants in the last exon, exon 33, of the NOTCH3 gene. Here, we present a 2-year-old girl for whom an early genomic analysis allowed us to recognize the presence of lateral meningoceles and to begin early monitoring of her condition for possible neurological complications. She had a characteristic facial appearance, hyperextensibility of the skin and mobility of the joints, and developmental delays. Given that lateral meningocele syndrome is a rare syndrome, the existence of lateral meningoceles is suspected only when the causative gene is detected by genetic testing. MRI scans are unlikely to be performed in infancy in the absence of neurological symptoms suggestive of meningoceles. No formal guidelines have been established for the neurosurgical indications for lateral meningocele syndrome. Given the features of hyperextensibility of the skin and hypermobility of the joints, lateral meningocele syndrome can be categorized as a connective tissue disease and may be progressive, as with the dural ectasia in Marfan syndrome and Loeys-Dietz syndrome. Watchful monitoring of dural ectasia may be warranted in patients with lateral meningocele syndrome.
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Anomalías Múltiples , Meningocele , Anomalías Múltiples/genética , Preescolar , Diagnóstico Precoz , Femenino , Genómica , Humanos , Lactante , Meningocele/diagnóstico por imagen , Meningocele/genéticaRESUMEN
PURPOSE: Several hundred genetic muscle diseases have been described, all of which are rare. Their clinical and genetic heterogeneity means that a genetic diagnosis is challenging. We established an international consortium, MYO-SEQ, to aid the work-ups of muscle disease patients and to better understand disease etiology. METHODS: Exome sequencing was applied to 1001 undiagnosed patients recruited from more than 40 neuromuscular disease referral centers; standardized phenotypic information was collected for each patient. Exomes were examined for variants in 429 genes associated with muscle conditions. RESULTS: We identified suspected pathogenic variants in 52% of patients across 87 genes. We detected 401 novel variants, 116 of which were recurrent. Variants in CAPN3, DYSF, ANO5, DMD, RYR1, TTN, COL6A2, and SGCA collectively accounted for over half of the solved cases; while variants in newer disease genes, such as BVES and POGLUT1, were also found. The remaining well-characterized unsolved patients (48%) need further investigation. CONCLUSION: Using our unique infrastructure, we developed a pathway to expedite muscle disease diagnoses. Our data suggest that exome sequencing should be used for pathogenic variant detection in patients with suspected genetic muscle diseases, focusing first on the most common disease genes described here, and subsequently in rarer and newly characterized disease genes.
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Exoma , Distrofia Muscular de Cinturas , Anoctaminas , Exoma/genética , Glucosiltransferasas , Humanos , Distrofia Muscular de Cinturas/genética , Secuenciación del ExomaRESUMEN
BACKGROUND: Renal hypouricemia (RHUC) is a hereditary disorder where mutations in SLC22A12 gene and SLC2A9 gene cause RHUC type 1 (RHUC1) and RHUC type 2 (RHUC2), respectively. These genes regulate renal tubular reabsorption of urates while there exist other genes counterbalancing the net excretion of urates including ABCG2 and SLC17A1. Urate metabolism is tightly interconnected with glucose metabolism, and SLC2A9 gene may be involved in insulin secretion from pancreatic ß-cells. On the other hand, a myriad of genes are responsible for the impaired insulin secretion independently of urate metabolism. CASE PRESENTATION: We describe a 67 year-old Japanese man who manifested severe hypouricemia (0.7 mg/dl (3.8-7.0 mg/dl), 41.6 µmol/l (226-416 µmol/l)) and diabetes with impaired insulin secretion. His high urinary fractional excretion of urate (65.5%) and low urinary C-peptide excretion (25.7 µg/day) were compatible with the diagnosis of RHUC and impaired insulin secretion, respectively. Considering the fact that metabolic pathways regulating urates and glucose are closely interconnected, we attempted to delineate the genetic basis of the hypouricemia and the insulin secretion defect observed in this patient using whole exome sequencing. Intriguingly, we found homozygous Trp258* mutations in SLC22A12 gene causing RHUC1 while concurrent mutations reported to be associated with hyperuricemia were also discovered including ABCG2 (Gln141Lys) and SLC17A1 (Thr269Ile). SLC2A9, that also facilitates glucose transport, has been implicated to enhance insulin secretion, however, the non-synonymous mutations found in SLC2A9 gene of this patient were not dysfunctional variants. Therefore, we embarked on a search for causal mutations for his impaired insulin secretion, resulting in identification of multiple mutations in HNF1A gene (MODY3) as well as other genes that play roles in pancreatic ß-cells. Among them, the Leu80fs in the homeobox gene NKX6.1 was an unreported mutation. CONCLUSION: We found a case of RHUC1 carrying mutations in SLC22A12 gene accompanied with compensatory mutations associated with hyperuricemia, representing the first report showing coexistence of the mutations with opposed potential to regulate urate concentrations. On the other hand, independent gene mutations may be responsible for his impaired insulin secretion, which contains novel mutations in key genes in the pancreatic ß-cell functions that deserve further scrutiny.
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Complicaciones de la Diabetes/genética , Proteínas Facilitadoras del Transporte de la Glucosa/genética , Transportadores de Anión Orgánico/genética , Proteínas de Transporte de Catión Orgánico/genética , Defectos Congénitos del Transporte Tubular Renal/genética , Cálculos Urinarios/genética , Anciano , Complicaciones de la Diabetes/complicaciones , Complicaciones de la Diabetes/patología , Glucosa/metabolismo , Factor Nuclear 1-alfa del Hepatocito/genética , Heterocigoto , Proteínas de Homeodominio/genética , Homocigoto , Humanos , Insulina/biosíntesis , Insulina/genética , Secreción de Insulina/genética , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/patología , Masculino , Mutación/genética , Defectos Congénitos del Transporte Tubular Renal/complicaciones , Defectos Congénitos del Transporte Tubular Renal/patología , Ácido Úrico/metabolismo , Cálculos Urinarios/complicaciones , Cálculos Urinarios/patología , Secuenciación del ExomaRESUMEN
The utility of whole exome analysis has been extensively demonstrated in research settings, but its clinical utility as a first-tier genetic test has not been well documented from diagnostic and health economic standpoints in real-life clinical settings. We performed medical exome analyses focusing on a clinically interpretable portion of the genome (4,813 genes) as a first-tier genetic test for 360 consecutive patients visiting a genetics clinic at a tertiary children's hospital in Japan, over a 3-year period. Bioinformatics analyses were conducted using standard software. A molecular diagnosis was made in 171 patients involving a total of 107 causative genes. Among these 107 causative genes, 57 genes were classified as genes with potential organ-specific interventions and management strategies. Clinically relevant results were obtained in 26% of the total cohort and 54% of the patients with a definitive molecular diagnosis. Performing the medical exome analysis at the time of the initial visit to the tertiary center, rather than after visits to pertinent specialists, brain MRI examination, and G-banded chromosome testing, would have reduced the financial cost by 197 euros according to retrospective calculation under multiple assumption. The present study demonstrated a high diagnostic yield (47.5%) for singleton medical exome analysis as a first-tier test in a real-life setting. Medical exome analysis yielded clinically relevant information in a quarter of the total patient cohort. The application of genomic testing during the initial visit to a tertiary medical center could be a rational approach to the diagnosis of patients with suspected genetic disorders.
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Secuenciación del Exoma/economía , Enfermedades Genéticas Congénitas/diagnóstico , Pruebas Genéticas/economía , Anomalías Múltiples/diagnóstico , Anomalías Múltiples/genética , Encéfalo/diagnóstico por imagen , Preescolar , Estudios de Cohortes , Biología Computacional , Análisis Costo-Beneficio , Enfermedades Genéticas Congénitas/economía , Enfermedades Genéticas Congénitas/genética , Pruebas Genéticas/métodos , Humanos , Lactante , Japón , Imagen por Resonancia Magnética , Centros de Atención Terciaria , Secuenciación del Exoma/métodosRESUMEN
Shwachman-Diamond syndrome characterized by metaphyseal dysplasia, pancreatic insufficiency, and pancytopenia is caused by biallelic mutations in SBDS. Gene conversion between SBDS and its pseudogene SBDSP1 is the major cause. Here, we report two unrelated patients with Shwachman-Diamond syndrome who were shown to be compound heterozygotes for relatively frequent pathogenic alleles (the 258+2T>C allele and another allele composed of 183-184TA>CT and 201A>G) using an established polymerase chain reaction sequencing assay with SBDS-specific primers. Exome analysis of the patients showed discrepant results: 258+2T>C with variant allele frequency around 0.85, and no variants detected for the 183-184TA>CT allele. Parental exome analysis of the two families further supported this notion. Confronted with two patients with an unexpected segregation pattern, we performed a transcriptome analysis of peripheral blood-derived mRNA to demonstrate that the results were compatible with those obtained using SBDS-specific PCR primers. Both alleles could be accounted for by gene conversion events. The diagnostic discrepancy can be accounted for by a decreased efficiency in the computational mapping of the reads with 183-184TA>CT and 201A>G to the reference sequence of the SBDS locus during exome analysis. This report highlights the pitfall of exome analysis for genes with pseudogenes, such as SBDS and the alternative use of RNA-seq is recommended to circumvent this problem.
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Secuenciación del Exoma , Proteínas/genética , Seudogenes/genética , Síndrome de Shwachman-Diamond/diagnóstico , Síndrome de Shwachman-Diamond/genética , Cartilla de ADN , Femenino , Perfilación de la Expresión Génica , Frecuencia de los Genes , Humanos , Lactante , Recién Nacido , Masculino , ARN Mensajero/genéticaRESUMEN
PURPOSE: Develop an automated exome analysis workflow that can produce a very small number of candidate variants yet still detect different numbers of deleterious variants between probands and unaffected siblings. METHODS: Ninety-seven outbred nuclear families from the Undiagnosed Diseases Program/Network included single probands and the corresponding unaffected sibling(s). Single-nucleotide polymorphism (SNP) chip and exome analyses were performed on all, with proband and unaffected sibling considered independently as the target. The total burden of candidate genetic variants was summed for probands and siblings over all considered disease models. RESULTS: Exome analysis workflow include automated programs for ethnicity-matched genotype calling, salvage pathway for Mendelian inconsistency, compound heterozygous recessive detection, BAM file regional curation, population frequency filtering, pedigree-aware BAM file noise evaluation, and exon deletion filtration. This workflow relied heavily on BAM file analysis. A greater average pathogenic variant number was found compared with unaffected siblings. This was significant (p < 0.05) when using published recommended thresholds, and implies that causal variants are retained in many probands' lists. CONCLUSION: Using Mendelian and non-Mendelian models, this agnostic exome analysis shows a difference between a small group of probands and their unaffected siblings. This workflow produces candidate lists small enough to pursue with laboratory validation.
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Variaciones en el Número de Copia de ADN/genética , Procesamiento Automatizado de Datos , Enfermedades Genéticas Congénitas/diagnóstico , Análisis de Secuencia de ADN , Exoma/genética , Exones/genética , Femenino , Enfermedades Genéticas Congénitas/genética , Genotipo , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Masculino , Linaje , Fenotipo , Polimorfismo de Nucleótido Simple/genética , Eliminación de Secuencia/genética , HermanosRESUMEN
BACKGROUND & AIMS: Obliterative portal venopathy (OPV) is characterized by lesions of portal vein intrahepatic branches and is thought to be responsible for many cases of portal hypertension in the absence of cirrhosis or obstruction of large portal or hepatic veins. In most cases the cause of OPV remains unknown. The aim was to identify a candidate gene of OPV. METHODS: Whole exome sequencing was performed in two families, including 6 patients with OPV. Identified mutations were confirmed by Sanger sequencing and expression of candidate gene transcript was studied by real time qPCR in human tissues. RESULTS: In both families, no mutations were identified in genes previously reported to be associated with OPV. In each family, we identified a heterozygous mutation (c.1783G>A, p.Gly595Arg and c.4895C>T, p.Thr1632Ile) in a novel gene located on chromosome 4, that we called FOPV (Familial Obliterative Portal Venopathy), and having a cDNA coding for 1793 amino acids. The FOPV mutations segregated with the disease in families and the pattern of inheritance was suggestive of autosomal dominant inherited OPV, with incomplete penetrance and variable expressivity. In silico analysis predicted a deleterious effect of each mutant and mutations concerned highly conserved amino acids in mammals. A deleterious heterozygous FOPV missense mutation (c.4244T>C, p.Phe1415Ser) was also identified in a patient with non-familial OPV. Expression study in liver veins showed that FOPV transcript was mainly expressed in intrahepatic portal vein. CONCLUSIONS: This report suggests that FOPV mutations may have a pathogenic role in some cases of familial and non-familial OPV.
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Hipertensión Portal/genética , Mutación , Vena Porta/patología , Proteínas/genética , Enfermedades Vasculares/genética , Adulto , Niño , Preescolar , Constricción Patológica , Femenino , Estudios de Asociación Genética , Marcadores Genéticos , Predisposición Genética a la Enfermedad , Herencia , Heterocigoto , Humanos , Hipertensión Portal/diagnóstico , Hipertensión Portal/patología , Lactante , Masculino , Persona de Mediana Edad , Linaje , Fenotipo , Enfermedades Vasculares/diagnóstico , Enfermedades Vasculares/patología , Adulto JovenRESUMEN
BACKGROUND: Leigh Syndrome (LS, OMIM 256000) is an early-onset, progressive neurodegenerative disorder characterized by broad clinical and genetic heterogeneity; it is the most frequent disorder of mitochondrial energy production in children. LS inheritance is complex because patients may present mutations in mitochondrial DNA (mtDNA) or in nuclear genes, which predominantly encode proteins involved in respiratory chain structure and assembly or in coenzyme Q10 biogenesis. However, during the last 15 years, the discovery of several genetic mutations and improved knowledge of the natural history of LS has significantly increased our understanding of this mitochondrial disorder. CASE PRESENTATION: Here we describe a 19-year-old male with clinical and neuroimaging LS diagnosed at 3 years of age. Genetic analyses of the whole mtDNA for maternally inherited LS (MILS) and neuropathy ataxia retinitis pigmentosa (NARP) syndrome failed to reveal any pathogenic mutations. CONCLUSIONS: Recently, a missense mutation in ECHS1 and a ~ 35 kb deletion in 10q26.3 involving the region including the gene were identified by WES (whole exome sequencing), uncovering the genetic diagnosis clinically hypothesized for 15 years. We also report the long-term follow-up of this patient, showing a comparison with classical LS or other Leigh-like pictures.
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Secuenciación de Nucleótidos de Alto Rendimiento , Enfermedad de Leigh , Secuenciación Completa del Genoma , Adolescente , Heterogeneidad Genética , Humanos , Enfermedad de Leigh/diagnóstico , Enfermedad de Leigh/genética , MasculinoRESUMEN
A broad range of genetic and non-genetic factors can lead to kidney injury that manifests as focal segmental glomerulosclerosis (FSGS), which can be classified into primary (idiopathic) and secondary forms. Previous genetic approaches to familial or sporadic cases of FSGS or steroid-resistant nephrotic syndrome identified causal mutations in a subset of genes. Recently, next-generation sequencing (NGS) approaches are becoming a part of a standard assessment in medical genetics. Current knowledge of the comprehensive genomic information is changing the way we think about FSGS and draws attention not only to identification of novel causal genes, but also to potential roles for combinations of mutations in multiple genes, mutations with complex inheritance, and susceptibility genes with variable penetrance carrying relatively minor but significant effects. This review provides an update on recent advances in the genetic analysis of FSGS and highlights the potential as well as the new challenges of NGS for diagnosis and mechanism-based treatment of FSGS.
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Glomeruloesclerosis Focal y Segmentaria/genética , Síndrome Nefrótico/congénito , Análisis de Secuencia de ADN , Glomeruloesclerosis Focal y Segmentaria/diagnóstico , Glomeruloesclerosis Focal y Segmentaria/terapia , Humanos , Síndrome Nefrótico/diagnóstico , Síndrome Nefrótico/genética , Síndrome Nefrótico/terapia , PenetranciaRESUMEN
The BrafV637E mutation is frequently reported in mouse hepatic tumors, depending on the mouse strain, and corresponds to the human BrafV600E mutation. In this study, we detected the BrafV637E mutation by whole-exome analysis in 4/4 hepatic tumors induced by neonatal treatment with diethylnitrosamine (DEN) in male B6C3F1 mice. We also detected the BrafV637E mutation in 54/63 (85.7%) hepatic lesions, including microscopic foci and grossly visible tumors, by PCR-direct sequencing. Although the mutation was detected in 5/7 (71.4%) hepatic tumors induced by neonatal DEN treatment followed by repeated CCl4 administration, it was not detected in 24 tumors induced by CCl4 treatment without DEN or in eight spontaneous lesions in B6C3F1 mice, suggesting that the mutation is induced by the genotoxic action of DEN. The DEN-induced tumors exhibited hyperphosphorylation of ERK1 and Akt, suggesting that the BrafV637E mutation might activate the MAPK and Akt pathways. Moreover, the DEN-induced tumors overexpressed mRNAs for the oncogene-induced senescence (OIS) markers such as p15Ink4b and p19Arf as well as pro-survival/pro-proliferative cytokines/chemokines such as complement C5/C5a, ICAM-1, IL-1 receptor antagonist and CXCL9, suggesting that the BrafV637E mutation influences the expression of genes involved in either OIS or cellular growth/survival. Liver-specific expression of mutated Braf under control of the albumin enhancer/promoter resulted in an enlarged liver that consisted entirely of small basophilic hepatocytes resembling DEN-induced preneoplastic hepatocytes with ERK1/Akt hyperphosphorylation and C5/C5a overexpression. These results indicate that the BrafV637E mutation induces hepatocytic changes in DEN-induced hepatic tumors. © 2016 The Authors. Molecular Carcinogenesis published by Wiley Periodicals, Inc.
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Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patología , Hígado/patología , Mutación Puntual , Proteínas Proto-Oncogénicas B-raf/genética , Animales , Carcinogénesis/inducido químicamente , Carcinogénesis/genética , Carcinogénesis/patología , Ciclo Celular , Citocinas/análisis , Dietilnitrosamina , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Hígado/efectos de los fármacos , Hígado/metabolismo , Neoplasias Hepáticas/inducido químicamente , Masculino , Ratones Endogámicos C57BL , Ratones TransgénicosRESUMEN
Mitochondrial encephalopathies are a heterogeneous group of disorders that, usually carry grave prognosis. Recently a homozygous mutation, Gly372Ser, in the TIMM50 gene, was reported in an abstract form, in three sibs who suffered from intractable epilepsy and developmental delay accompanied by 3-methylglutaconic aciduria. We now report on four patients from two unrelated families who presented with severe intellectual disability and seizure disorder, accompanied by slightly elevated lactate level, 3-methylglutaconic aciduria and variable deficiency of mitochondrial complex V. Using exome analysis we identified two homozygous missense mutations, Arg217Trp and Thr252Met, in the TIMM50 gene. The TIMM50 protein is a subunit of TIM23 complex, the mitochondrial import machinery. It serves as the major receptor in the intermembrane space, binding to proteins which cross the mitochondrial inner membrane on their way to the matrix. The mutations, which affected evolutionary conserved residues and segregated with the disease in the families, were neither present in large cohorts of control exome analyses nor in our ethnic specific exome cohort. Given the phenotypic similarity, we conclude that missense mutations in TIMM50 are likely manifesting by severe intellectual disability and epilepsy accompanied by 3-methylglutaconic aciduria and variable mitochondrial complex V deficiency. 3-methylglutaconic aciduria is emerging as an important biomarker for mitochondrial dysfunction, in particular for mitochondrial membrane defects.
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Adenosina Trifosfatasas/deficiencia , Epilepsia/genética , Proteínas de la Membrana/deficiencia , Proteínas de Transporte de Membrana/genética , Errores Innatos del Metabolismo/genética , Encefalomiopatías Mitocondriales/genética , Adenosina Trifosfatasas/genética , Proteínas Portadoras/genética , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Proteínas de la Membrana/genética , Proteínas del Complejo de Importación de Proteínas Precursoras Mitocondriales , ATPasas de Translocación de Protón Mitocondriales , Mutación , Polimorfismo de Nucleótido Simple , EmbarazoRESUMEN
This study investigated rare variants associated with atopic dermatitis. We performed exome analyses on 37 patients who were diagnosed with atopic dermatitis by board-certified dermatologists and had total serum IgE levels greater than 1000 IU/ml. The exome analysis identified seven variants with <1% allele frequency in Asian (ASN) population of 1000 Genomes Project phase 1 data and >5% allele frequency in the atopic dermatitis exome samples. We then conducted a replication study using 469 atopic dermatitis patients with total serum IgE ≥1000 IU/ml and 935 Japanese controls to assess the presence of these 7 candidate variants. The replication study confirmed that CYP27A1 rs199691576 (A/G) was associated with atopic dermatitis with high serum IgE levels (P = 0.012, odds ratio = 2.1). CYP27A1 is involved in the metabolism of vitamin D3, which plays important roles in modulating immune function. Previous studies have reported polymorphisms in vitamin D pathway genes that are associated with allergy-related phenotypes. Our data confirm the importance of genes regulating the vitamin D pathway in the development of atopic dermatitis.
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Colestanotriol 26-Monooxigenasa/genética , Dermatitis Atópica/sangre , Dermatitis Atópica/genética , Predisposición Genética a la Enfermedad , Variación Genética , Inmunoglobulina E/sangre , Adulto , Alelos , Dermatitis Atópica/inmunología , Femenino , Frecuencia de los Genes , Genotipo , Humanos , Inmunoglobulina E/inmunología , Masculino , Mutación Missense , Oportunidad Relativa , Polimorfismo de Nucleótido Simple , Adulto JovenRESUMEN
The genetic basis of numerous intellectual disability (ID) syndromes has recently been identified by applying exome analysis on a research or clinical basis. There is significant clinical overlap of biologically related syndromes, as exemplified by Nicolaides-Baraitser (NCBRS) and Coffin-Siris (CSS) syndrome. Both result from mutations affecting the BAF (mSWI/SNF) complex and belong to the growing category of BAFopathies. In addition to the notable clinical overlap between these BAFopathies, heterogeneity exists for patients clinically diagnosed with one of these conditions. We report two teenagers with ID whose molecular diagnosis of a SMARC2A or ARID1B mutation, respectively, was established through clinical exome analysis. Interestingly, using only the information provided in a single clinically obtained facial photograph from each patient, the facial dysmorphology analysis detected similarities to facial patterns associated with NCBRS as the first suggestion for both individuals, followed by CSS as the second highest ranked in the individual with the ARID1B mutation. Had this information been available to the laboratory performing the exome analysis, it could have been utilized during the variant analysis and reporting process, in conjunction with the written summary provided with each test requisition. While the available massive parallel sequencing technology, variant calling and variant interpretation are constantly evolving, clinical information remains critical for this diagnostic process. When trio analysis is not feasible, additional diagnostic tools may become particularly valuable. Facial dysmorphology analysis data may supplement the clinical phenotype summary and provide data independent of the clinician's personal experience and bias. © 2016 Wiley Periodicals, Inc.
Asunto(s)
Anomalías Múltiples/diagnóstico , Anomalías Craneofaciales/diagnóstico , Proteínas de Unión al ADN/genética , Cara/anomalías , Deformidades Congénitas del Pie/diagnóstico , Deformidades Congénitas de la Mano/diagnóstico , Hipotricosis/diagnóstico , Discapacidad Intelectual/diagnóstico , Micrognatismo/diagnóstico , Atrofia Muscular/diagnóstico , Cuello/anomalías , Factores de Transcripción/genética , Anomalías Múltiples/genética , Anomalías Múltiples/fisiopatología , Adolescente , Anomalías Craneofaciales/genética , Anomalías Craneofaciales/fisiopatología , Exoma/genética , Cara/fisiopatología , Facies , Femenino , Deformidades Congénitas del Pie/genética , Deformidades Congénitas del Pie/fisiopatología , Deformidades Congénitas de la Mano/genética , Deformidades Congénitas de la Mano/fisiopatología , Humanos , Hipotricosis/genética , Hipotricosis/fisiopatología , Discapacidad Intelectual/genética , Discapacidad Intelectual/fisiopatología , Masculino , Micrognatismo/genética , Micrognatismo/fisiopatología , Atrofia Muscular/genética , Atrofia Muscular/fisiopatología , Mutación , Cuello/fisiopatología , Proteínas Nucleares/genética , Patología Molecular , FenotipoRESUMEN
There are no known genetic variants with large effects on susceptibility to major depressive disorder (MDD). Although one proposed study approach is to increase sensitivity by increasing sample sizes, another is to focus on families with multiple affected individuals to identify genes with rare or novel variants with strong effects. Choosing the family-based approach, we performed whole-exome analysis on affected individuals (n = 12) across five MDD families, each with at least five affected individuals, early onset, and prepubertal diagnoses. We identified 67 genes where novel deleterious variants were shared among affected relatives. Gene ontology analysis shows that of these 67 genes, 18 encode transcriptional regulators, eight of which are expressed in the human brain, including four KRAB-A box-containing Zn(2+) finger repressors. One of these, ZNF34, has been reported as being associated with bipolar disorder and as differentially expressed in bipolar disorder patients compared to healthy controls. We found a novel variant-encoding a non-conservative P17R substitution in the conserved repressor domain of ZNF34 protein-segregating completely with MDD in all available individuals in the family in which it was discovered. Further analysis showed a common ZNF34 coding indel segregating with MDD in a separate family, possibly indicating the presence of an unobserved, linked, rare variant in that particular family. Our results indicate that genes encoding transcription factors expressed in the brain might be an important group of MDD candidate genes and that rare variants in ZNF34 might contribute to susceptibility to MDD and perhaps other affective disorders.