scholarly journals UFM1 founder mutation in the Roma population causes recessive variant of H-ABC

Neurology ◽  
2017 ◽  
Vol 89 (17) ◽  
pp. 1821-1828 ◽  
Author(s):  
Eline M.C. Hamilton ◽  
Enrico Bertini ◽  
Luba Kalaydjieva ◽  
Bharti Morar ◽  
Dana Dojčáková ◽  
...  
Keyword(s):  
Single Nucleotide Polymorphism Array ◽  
Homozygosity Mapping ◽  
Homozygous Deletion ◽  
Epileptic Encephalopathy ◽  
Luciferase Reporter ◽  
Taqman Assay ◽  
Gene Defect ◽  
Luciferase Reporter Construct ◽  
Roma Population ◽  
Whole Exome

Objective:To identify the gene defect in patients with hypomyelination with atrophy of the basal ganglia and cerebellum (H-ABC) who are negative for TUBB4A mutations.Methods:We performed homozygosity mapping and whole exome sequencing (WES) to detect the disease-causing variant. We used a Taqman assay for population screening. We developed a luciferase reporter construct to investigate the effect of the promoter mutation on expression.Results:Sixteen patients from 14 families from different countries fulfilling the MRI criteria for H-ABC exhibited a similar, severe clinical phenotype, including lack of development and a severe epileptic encephalopathy. The majority of patients had a known Roma ethnic background. Single nucleotide polymorphism array analysis in 5 patients identified one large overlapping homozygous region on chromosome 13. WES in 2 patients revealed a homozygous deletion in the promoter region of UFM1. Sanger sequencing confirmed homozygosity for this variant in all 16 patients. All patients shared a common haplotype, indicative of a founder effect. Screening of 1,000 controls from different European Roma panels demonstrated an overall carrier rate of the mutation of 3%–25%. Transfection assays showed that the deletion significantly reduced expression in specific CNS cell lines.Conclusions:UFM1 encodes ubiquitin-fold modifier 1 (UFM1), a member of the ubiquitin-like family involved in posttranslational modification of proteins. Its exact biological role is unclear. This study associates a UFM1 gene defect with a disease and sheds new light on possible UFM1 functional networks.

scholarly journals XRCC2 mutation causes meiotic arrest, azoospermia and infertility

2018 ◽  
Vol 55 (9) ◽  
pp. 628-636 ◽  
Author(s):  
Yongjia Yang ◽  
Jihong Guo ◽  
Lei Dai ◽  
Yimin Zhu ◽  
Hao Hu ◽  
...  
Keyword(s):  
Animal Model ◽  
Essential Role ◽  
Homozygosity Mapping ◽  
Recessive Mutation ◽  
Obstructive Azoospermia ◽  
Gene Defect ◽  
Consanguineous Family ◽  
Meiotic Arrest ◽  
Whole Exome

BackgroundMeiotic homologous recombination (HR) plays an essential role in gametogenesis. In most eukaryotes, meiotic HR is mediated by two recombinase systems: ubiquitous RAD51 and meiosis-specific DMC1. In the RAD51-mediated HR system, RAD51 and five RAD51 paralogues are essential for normal RAD51 function, but the role of RAD51 in human meiosis is unclear. The knockout of Rad51 or any Rad51 paralogue in mice exhibits embryonic lethality. We investigated a family with meiotic arrest, azoospermia and infertility but without other abnormalities.MethodsHomozygosity mapping and whole-exome sequencing were performed in a consanguineous family. An animal model carrying a related mutation was created by using a CRISPR/Cas9 system.ResultsWe identified a 1 bp homozygous substitution (c.41T>C/p.Leu14Pro) on a RAD51 paralogue, namely, XRCC2, in the consanguineous family. We did not detect any XRCC2 recessive mutation in a cohort of 127 males with non-obstructive-azoospermia. Knockin mice with Xrcc2-c.T41C/p.Leu14Pro mutation were generated successfully by the CRISPR/Cas9 method. The homozygotes survived and exhibited meiotic arrest, azoospermia, premature ovarian failure and infertility.ConclusionA XRCC2 recessive mutation causing meiotic arrest and infertility in humans was duplicated with knockin mice. Our results revealed a new Mendelian hereditary entity and provided an experimental model of RAD51-HR gene defect in mammalian meiosis.

Five genetic polymorphisms of cytochrome P450 enzymes in the Czech non-Roma and Czech Roma population samples

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Lucie Dlouhá ◽  
Věra Adámková ◽  
Lenka Šedová ◽  
Věra Olišarová ◽  
Jaroslav A. Hubáček ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Genetic Polymorphisms ◽  
Metabolic Pathways ◽  
Cytochromes P450 ◽  
Taqman Assay ◽  
Cytochrome P450 Enzymes ◽  
Roma Population ◽  
Czech Population ◽  
Genotype Frequencies ◽  
Pcr Rflp

AbstractObjectivesCytochromes P450 play a role in human drugs metabolic pathways and their genes are among the most variable in humans. The aim of this study was to analyze genotype frequencies of five common polymorphisms of cytochromes P450 in Roma/Gypsy and Czech (non-Roma) population samples with Czech origin.MethodsRoma/Gypsy (n=302) and Czech subjects (n=298) were genotyped for CYP1A2 (rs762551), CYP2A6 (rs4105144), CYP2B6 (rs3745274) and CYP2D6 (rs3892097; rs1065852) polymorphisms using PCR-RFLP or Taqman assay.ResultsWe found significant allelic/genotype differences between ethnics in three genes. For rs3745274 polymorphism, there was increased frequency of T allele carriers in Roma in comparison with Czech population (53.1 vs. 43.7%; p=0.02). For rs4105144 (CYP2A6) there was higher frequency of T allele carriers in Roma in comparison with Czech population (68.7 vs. 49.8%; p<0.0001). For rs3892097 (CYP2D6) there was more carriers of the A allele between Roma in comparison with Czech population (39.2 vs. 38.2%; p=0.048). Genotype/allelic frequencies of CYP2D6 (rs1065852) and CYP1A2 (rs762551) variants did not significantly differ between the ethnics.ConclusionsThere were significant differences in allelic/genotype frequencies of some, but not all cytochromes P450 polymorphisms between the Czech Roma/Gypsies and Czech non-Roma subjects.

scholarly journals Pathogenic STX3 variants affecting the retinal and intestinal transcripts cause an early-onset severe retinal dystrophy in microvillus inclusion disease subjects

2021 ◽  
Author(s):  
Andreas R. Janecke ◽  
Xiaoqin Liu ◽  
Rüdiger Adam ◽  
Sumanth Punuru ◽  
Arne Viestenz ◽  
...  
Keyword(s):  
Early Onset ◽  
Single Nucleotide Polymorphism Array ◽  
Outer Nuclear Layer ◽  
Retinal Dystrophy ◽  
Geographic Origin ◽  
Retinal Disease ◽  
Homozygosity Mapping ◽  
Rod Photoreceptor ◽  
Loss Of Function ◽  
Knockout Mouse Model

AbstractBiallelic STX3 variants were previously reported in five individuals with the severe congenital enteropathy, microvillus inclusion disease (MVID). Here, we provide a significant extension of the phenotypic spectrum caused by STX3 variants. We report ten individuals of diverse geographic origin with biallelic STX3 loss-of-function variants, identified through exome sequencing, single-nucleotide polymorphism array-based homozygosity mapping, and international collaboration. The evaluated individuals all presented with MVID. Eight individuals also displayed early-onset severe retinal dystrophy, i.e., syndromic—intestinal and retinal—disease. These individuals harbored STX3 variants that affected both the retinal and intestinal STX3 transcripts, whereas STX3 variants affected only the intestinal transcript in individuals with solitary MVID. That STX3 is essential for retinal photoreceptor survival was confirmed by the creation of a rod photoreceptor-specific STX3 knockout mouse model which revealed a time-dependent reduction in the number of rod photoreceptors, thinning of the outer nuclear layer, and the eventual loss of both rod and cone photoreceptors. Together, our results provide a link between STX3 loss-of-function variants and a human retinal dystrophy. Depending on the genomic site of a human loss-of-function STX3 variant, it can cause MVID, the novel intestinal-retinal syndrome reported here or, hypothetically, an isolated retinal dystrophy.

scholarly journals Affordable Luciferase Reporter Assay for Cell-Based High-Throughput Screening

2012 ◽  
Vol 18 (4) ◽  
pp. 453-461 ◽  
Author(s):  
Ellen Siebring-van Olst ◽  
Christie Vermeulen ◽  
Renee X. de Menezes ◽  
Michael Howell ◽  
Egbert F. Smit ◽  
...  
Keyword(s):  
High Throughput ◽  
High Throughput Screening ◽  
Firefly Luciferase ◽  
Luciferase Assay ◽  
Luciferase Reporter ◽  
Chemical Components ◽  
Simple Liquid ◽  
Luciferase Reporter Construct ◽  
Reagent Cost ◽  
Firefly Luciferase Gene

The firefly luciferase gene is commonly used in cell-based reporter assays. Convenient luciferase assay reagents for use in high-throughput screening (HTS) are commercially available. However, the high cost of these reagents is not within the means of some academic laboratories. Therefore, we set out to develop an affordable luciferase assay reagent applicable in an HTS format using simple liquid-handling steps. The reagent was homemade from individual chemical components and optimized for luminescence intensity and stability. We determined the minimal concentrations of the most expensive components, dithiothreitol (DTT) and D-luciferin, resulting in a total assay reagent cost of less than 1 cent per sample. Signal stability was maximized by omission of coenzyme A and reduction of DTT concentration. The assay was validated in a high-throughput setting using two cancer cell lines carrying a p53-dependent luciferase reporter construct and siRNAs modulating p53 transcriptional activity. Induction of p53 activity by silencing PPM1D or SYVN1 and reduction of p53 activity by silencing p53 remained constant over a 2-h measurement period, with good assay quality (Z′ factors mostly above 0.5). Hence, the luciferase assay described herein can be used for affordable reporter readout in cell-based HTS.

Abstract 117: MicroRNA-138 regulates S100A1 in Endothelial Cells

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Anagha Sen ◽  
Shumei Ren ◽  
Jianxin Sun ◽  
Patrick Most ◽  
Karsten Peppel
Keyword(s):  
Gene Expression ◽  
Endothelial Cells ◽  
Reporter Gene ◽  
Recombinant Adenovirus ◽  
Limb Ischemia ◽  
Bioinformatic Analysis ◽  
Reporter Gene Expression ◽  
Luciferase Reporter ◽  
C2c12 Myotubes ◽  
Luciferase Reporter Construct

Rationale: The EF-hand Ca2+ sensor S100A1 is essential for proper endothelial nitric oxide (NO) synthase (eNOS) activation. S100A1 levels are greatly reduced in endothelial cells (ECs) subjected to hypoxia, rendering them dysfunctional. Objective: To determine if the 3’UTR mediates the rapid hypoxia-induced downregulation of S100A1 in ECs. Methods and Results: ECs transfected with a S100A1 - 3’ untranslated region (UTR) luciferase reporter construct displayed significantly reduced gene expression when subjected to gas or chemical hypoxia. Bioinformatic analysis suggested that microRNA -138 (miR-138) could target the 3’UTR of S100A1. Hypoxia greatly increased miR-138 levels in ECs, but not in skeletal muscle C2C12 myotubes. Consistent with this finding, patients with critical limb ischemia (CLI) or mice subjected to femoral artery resection (FAR) displayed increased miR-138 levels. Transfection of a miR-138 mimic into ECs reduced S100A1 - 3 ‘UTR reporter gene expression, while transfection of an anti miR-138 (antagomir) prevented the hypoxia-induced downregulation of the reporter gene. The increased levels of miR-138 are dependent on Hif1-α activation as treatment with siRNA against Hif1-α prevented S100A1 reporter gene downregulation after hypoxia. Conversely, specific activation of Hif1-α by a selective prolyl-hydroxylase inhibitor (IOX2) reduced reporter gene expression. Finally, ECs transfected with miR-138 mimic displayed reduced tube formation when plated onto Matrigel matrix and expressed less NO when stimulated with VEGF. These effects were reversed by gene transfer of S100A1 using recombinant adenovirus. Conclusions: Our study shows that miR-138 is an essential mediator of EC dysfunction via its ability to target the 3’UTR of S100A1 in a hypoxia-induced manner. MiR-138 might thus be an attractive target for the treatment of pathologies that are linked to endothelial dysfunction.

RHOBTB2 p.Arg511Trp Mutation in Early Infantile Epileptic Encephalopathy-64: Review and Case Report

2021 ◽  
Author(s):  
J Fonseca ◽  
C Melo ◽  
C Ferreira ◽  
M Sampaio ◽  
R Sousa ◽  
...  
Keyword(s):  
Case Report ◽  
Intellectual Disability ◽  
Status Epilepticus ◽  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Epileptic Encephalopathy ◽  
Btb Domain ◽  
Pathogenic Variants ◽  
Severe Intellectual Disability ◽  
Whole Exome

AbstractEarly infantile epileptic encephalopathy-64 (EIEE 64), also called RHOBTB2-related developmental and epileptic encephalopathy (DEE), is caused by heterozygous pathogenic variants (EIEE 64; MIM#618004) in the Rho-related BTB domain-containing protein 2 (RHOBTB2) gene. To date, only 13 cases with RHOBTB2-related DEE have been reported. We add to the literature the 14th case of EIEE 64, identified by whole exome sequencing, caused by a heterozygous pathogenic variant in RHOBTB2 (c.1531C > T), p.Arg511Trp. This additional case supports the main features of RHOBTB2-related DEE: infantile-onset seizures, severe intellectual disability, impaired motor functions, postnatal microcephaly, recurrent status epilepticus, and hemiparesis after seizures.

scholarly journals High-Frequency Exon Deletion of DNA Cross-Link Repair 1C Accounting for Severe Combined Immunodeficiency May Be Missed by Whole-Exome Sequencing

2021 ◽  
Vol 12 ◽  
Author(s):  
Feifan Xiao ◽  
Yulan Lu ◽  
Bingbing Wu ◽  
Bo Liu ◽  
Gang Li ◽  
...  
Keyword(s):  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Rare Variant ◽  
Severe Combined Immunodeficiency ◽  
Cell Receptor ◽  
Homozygous Deletion ◽  
Combined Immunodeficiency ◽  
Cross Link ◽  
Single Nucleotide Variants ◽  
Whole Exome

Next-generation sequencing (NGS) has been used to detect severe combined immunodeficiency (SCID) in patients, and some patients with DNA cross-link repair 1C (DCLRE1C) variants have been identified. Moreover, some compound variants, such as copy number variants (CNV) and single nucleotide variants (SNV), have been reported. The purpose of this study was to expand the genetic data related to patients with SCID carrying the compound DCLRE1C variant. Whole-exome sequencing (WES) was performed for genetic analysis, and variants were verified by performing Sanger sequencing or quantitative PCR. Moreover, we searched PubMed and summarized the data of the reported variants. Four SCID patients with DCLRE1C variants were identified in this study. WES revealed a homozygous deletion in the DCLRE1C gene from exons 1–5 in patient 1, exons 1–3 deletion and a novel rare variant (c.92T&gt;C, p.L31P) in patient 2, exons 1–3 deletion and a novel rare variant (c.328C&gt;G, p.L110V) in patient 3, and exons 1–4 deletion and a novel frameshift variant (c.449dup, p.His151Alafs*20) in patient 4. Based on literature review, exons 1–3 was recognized as a hotspot region for deletion variation. Moreover, we found that compound variations (CNV + SNV) accounted for approximately 7% variations in all variants. When patients are screened for T-cell receptor excision circles (TRECs), NGS can be used to expand genetic testing. Deletion of the DCLRE1C gene should not be ignored when a variant has been found in patients with SCID.

scholarly journals Glucose enhances insulin promoter activity in MIN6 β-cells independently of changes in intracellular Ca2+ concentration and insulin secretion

1999 ◽  
Vol 342 (2) ◽  
pp. 275-280 ◽  
Author(s):  
Helen J. KENNEDY ◽  
Imran RAFIQ ◽  
Aristea E. POULI ◽  
Guy A. RUTTER
Keyword(s):  
Promoter Activity ◽  
Photon Counting ◽  
Firefly Luciferase ◽  
Receptor Activation ◽  
Luciferase Reporter ◽  
Β Cells ◽  
Viral Promoter ◽  
Luciferase Reporter Construct ◽  
Insulin Promoter ◽  
Firefly Luciferase Reporter

Recent studies have suggested that glucose may activate insulin gene transcription through increases in intracellular Ca2+ concentration, possibly acting via the release of stored insulin. We have investigated this question by dynamic photon-counting imaging of insulin- and c-fos-promoter-firefly luciferase reporter construct activity. Normalized to constitutive viral promoter activity, insulin promoter activity in MIN6 β-cells was increased 1.6-fold after incubation at 30 mM compared with 3 mM glucose, but was unaltered at either glucose concentration by the presence of insulin (100 nM) or the Ca2+ channel inhibitor, verapamil (100 μM). Increases in intracellular [Ca2+] achieved by plasma membrane depolarization with KCl failed to enhance either insulin or c-fos promoter activity in MIN6 cells, but increased c-fos promoter activity 5-fold in AtT20 cells. Together, these results demonstrate that glucose can exert a direct effect on insulin promoter activity in islet β-cells, via a signalling pathway which does not require increases in intracellular [Ca2+] nor insulin release and insulin receptor activation.

Mapping and functional analysis of an instability element in phosphoenolpyruvate carboxykinase mRNA

2000 ◽  
Vol 279 (5) ◽  
pp. F866-F873 ◽  
Author(s):  
Omar F. Laterza ◽  
Lynn Taylor ◽  
Shashikala Unnithan ◽  
Ly Nguyen ◽  
Norman P. Curthoys
Keyword(s):  
Phosphoenolpyruvate Carboxykinase ◽  
Luciferase Activity ◽  
Specific Protein ◽  
Luciferase Reporter ◽  
Reporter Construct ◽  
Luciferase Reporter Construct ◽  
Functional Studies ◽  
Renal Gluconeogenesis ◽  
Shift Analysis ◽  
Nontranslated Region

Phosph oenolpyruvate carboxykinase (PEPCK) is a key regulatory enzyme of renal gluconeogenesis. The 3′-nontranslated region of the PEPCK mRNA contains an instability element that facilitates its rapid turnover and contributes to the regulation of PEPCK gene expression. Such processes are mediated by specific protein-binding elements. Thus RNA gel shift analysis was used to identify proteins in rat renal cortical cytosolic extracts that bind to the 3′-nontranslated region of the PEPCK mRNA. Deletion constructs were then used to map the binding interactions to two adjacent RNA segments (PEPCK-6 and PEPCK-7). However, competition experiments established that only the binding to PEPCK-7 was specific. Functional studies were performed by cloning similar segments in a luciferase reporter construct, pLuc/Zeo. This analysis indicated that both PEPCK-6 and PEPCK-7 segments were necessary to produce a decrease in luciferase activity equivalent to that observed with the full-length 3′-nontranslated region. Thus the PEPCK-7 segment binds a specific protein that may recruit one or more proteins to form a complex that mediates the rapid decay of the PEPCK mRNA.

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