Validation of Polymerase Chain Reaction–Based Assay to Detect Actual Number of CGG Repeats in FMR1 Gene in Indian Fragile X Syndrome Patients

2016 ◽  
Vol 32 (4) ◽  
pp. 371-378
Author(s):  
Madhumita Roy Chowdhury ◽  
Sandeepa Chauhan ◽  
Anjali Dabral ◽  
B. K. Thelma ◽  
Neerja Gupta ◽  
...  
Keyword(s):  
Indian Population ◽  
Fragile X ◽  
Molecular Genetic ◽  
Turnaround Time ◽  
Primary Objective ◽  
Carrier Status ◽  
Rapid Pcr ◽  
Cgg Repeats ◽  
Polymerase Chain ◽  
Agg Interruptions

Molecular genetic testing for fragile X (FX) is complicated due to the large variation in the size of CGG expansion. The aim of this study was to apply this new technique using AmplideX FMR1 PCR assay, which is considered a better diagnostic tool for detecting expanded alleles in Indian population. The primary objective was to identify the carrier status of females and to correlate the instability of premutation alleles in females with the repeat sizes. 24 children with FX based on rapid PCR and 29 female relatives of these patients were included. Out of the 29 females screened, those whose child (or children) was affected by FX, were all premutation carriers confirming their role in transmission. The smallest PM allele that expanded into FM in the next generation was 78 repeats and the smallest PM allele detected was 63 repeats, and when transmitted from mother to offspring remained in the premutation range. In 4 families, the repeat size of the allele reduced from PM to normal repeat numbers in their daughters and in 1 case to borderline PM range. Thus, apart from the reduced turnaround time, this PCR based assay offers advantage by its sensitivity to detect CGG repeats in the intermediate region and lower range of premutation alleles. It also provides added information of AGG interruptions, which may have an impact on the counseling of women with intermediate and PM alleles.

scholarly journals Metabolomic Biomarkers Are Associated With Area of the Pons in Fragile X Premutation Carriers at Risk for Developing FXTAS

2021 ◽  
Vol 12 ◽  
Author(s):  
Marwa Zafarullah ◽  
Blythe Durbin-Johnson ◽  
Emily S. Fourie ◽  
David R. Hessl ◽  
Susan M. Rivera ◽  
...  
Keyword(s):  
Neurodegenerative Disorder ◽  
Fragile X ◽  
Brain Area ◽  
Ultra Performance Liquid Chromatography ◽  
Primary Objective ◽  
Pcr Analysis ◽  
Mass Analyzer ◽  
Cgg Repeat ◽  
Cgg Repeats ◽  
Metabolic Signatures

Fragile X-associated tremor/ataxia syndrome (FXTAS) is a late adult-onset neurodegenerative disorder that affects movement and cognition in male and female carriers of a premutation allele (55–200 CGG repeats; PM) in the fragile X mental retardation (FMR1) gene. It is currently unknown how the observed brain changes are associated with metabolic signatures in individuals who develop the disorder over time. The primary objective of this study was to investigate the correlation between longitudinal changes in the brain (area of the pons, midbrain, and MCP width) and the changes in the expression level of metabolic biomarkers of early diagnosis and progression of FXTAS in PM who, as part of an ongoing longitudinal study, emerged into two distinct categories. These included those who developed symptoms of FXTAS (converters, CON) at subsequent visits and those who did not meet the criteria of diagnosis (non-converters, NCON) and were compared to age-matched healthy controls (HC). We assessed CGG repeat allele size by Southern Blot and PCR analysis. Magnetic Resonance Imaging (MRIs) acquisition was obtained on a 3T Siemens Trio scanner and metabolomic profile was obtained by ultra-performance liquid chromatography, accurate mass spectrometer, and an Orbitrap mass analyzer. Our findings indicate that differential metabolite levels are linked with the area of the pons between healthy control and premutation groups. More specifically, we observed a significant association of ceramides and mannonate metabolites with a decreased area of the pons, both at visit 1 (V1) and visit 2 (V2) only in the CON as compared to the NCON group suggesting their potential role in the development of the disorder. In addition, we found a significant correlation of these metabolic signatures with the FXTAS stage at V2 indicating their contribution to the progression and pathogenesis of FXTAS. Interestingly, these metabolites, as part of lipid and sphingolipid lipids pathways, provide evidence of the role that their dysregulation plays in the development of FXTAS and inform us as potential targets for personalized therapeutic development.

scholarly journals Unique AGG Interruption in the CGG Repeats of the FMR1 Gene Exclusively Found in Asians Linked to a Specific SNP Haplotype

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Pornprot Limprasert ◽  
Janpen Thanakitgosate ◽  
Kanoot Jaruthamsophon ◽  
Thanya Sripo
Keyword(s):  
Genetic Background ◽  
Fragile X ◽  
Cgg Repeat ◽  
Direct Dna Sequencing ◽  
Asian Populations ◽  
Cgg Repeats ◽  
Normal Individuals ◽  
The Common ◽  
Almost All ◽  
Agg Interruptions

Fragile X syndrome (FXS) is the most common inherited intellectual disability. It is caused by the occurrence of more than 200 pure CGG repeats in the FMR1 gene. Normal individuals have 6–54 CGG repeats with two or more stabilizing AGG interruptions occurring once every 9- or 10-CGG-repeat blocks in various populations. However, the unique (CGG)6AGG pattern, designated as 6A, has been exclusively reported in Asians. To examine the genetic background of AGG interruptions in the CGG repeats of the FMR1 gene, we studied 8 SNPs near the CGG repeats in 176 unrelated Thai males with 19–56 CGG repeats. Of these 176 samples, we identified AGG interruption patterns from 95 samples using direct DNA sequencing. We found that the common CGG repeat groups (29, 30, and 36) were associated with 3 common haplotypes, GCGGATAA (Hap A), TTCATCGC (Hap C), and GCCGTTAA (Hap B), respectively. The configurations of 9A9A9, 10A9A9, and 9A9A6A9 were commonly found in chromosomes with 29, 30, and 36 CGG repeats, respectively. Almost all chromosomes with Hap B (22/23) carried at least one 6A pattern, suggesting that the 6A pattern is linked to Hap B and may have originally occurred in the ancestors of Asian populations.

Parkinson’s Disease or Essential Tremor?

2016 ◽  
Author(s):  
Richard A. Walsh
Keyword(s):  
Cognitive Impairment ◽  
Essential Tremor ◽  
Fragile X ◽  
Neurodevelopmental Disorder ◽  
Older Men ◽  
Repeat Expansion ◽  
Carrier Status ◽  
Full Mutation ◽  
Cgg Repeats ◽  
Ataxia Syndrome

Fragile X-associated tremor ataxia syndrome is a heredodegenerative syndrome that presents in older men as a tremor syndrome with less prominent ataxia and cognitive impairment initially. The underlying genetic cause, a premutation in the FMR1 gene, results in a toxic accumulation of mRNA. The full mutation, a triple-repeat expansion of more than 200 CGG repeats, gives rise to a reduction in FMR1 protein expression and fragile X, a neurodevelopmental disorder that may be identified in successive male generations. The prevalence of carrier status is high in the general population, and it is likely that most movement disorders clinics will have one or more patients with this syndrome, potentially carrying a label of essential tremor.

A Study of the Efficiency of Modern Domestic Disinfectants in the System of TB Control Activities

2015 ◽  
Vol 2 (2) ◽  
pp. 26-31 ◽  
Author(s):  
A. Paliy ◽  
A. Zavgorodniy ◽  
B. Stegniy ◽  
A. Gerilovych
Keyword(s):  
Molecular Genetic ◽  
Critical Role ◽  
Bactericidal Effect ◽  
Chain Reaction ◽  
Tb Control ◽  
Source Of Infection ◽  
Polymerase Chain ◽  
And Control ◽  
Chemical Groups ◽  
Test Objects

Due to the absence of elaborated effi cient means for specifi c prevention of bovine tuberculosis, it is ex- tremely important to detect and eliminate the source of infection and to take veterinary and sanitary preven- tive measures. Here the critical role is attributed to disinfection, which breaks the epizootic chain due to the elimination of pathogenic microorganisms in the environment and involves the application of disinfectants of different chemical groups. Aim. To study the tuberculocidal properties of new disinfectants DZPT-2 and FAG against atypical mycobacteria Mycobacterium fortitum and a TB agent Mycobacterium bovis. Methods. The bacteriological and molecular-genetic methods were used. Results. It was determined that DZPT-2 prepara- tion has bactericidal effect on M. fortuitum when used in the concentration of 2.0 % of the active ingredient (AI) when exposed for 5–24 h, while disinfectant FAG has a bactericidal effect in the concentration of 2.0 % when exposed for 24 h. Disinfectant DZPT-2 in the concentration of 2.0 % of the AI, when exposed for 5–24 h, and FAG preparation in the concentration of 2.0 %, when exposed for 24 h, and with the norm of consump- tion rate of 1 cubic decimeter per 1 square meter disinfect the test-objects (batiste, wood, glazed tile, metal, glass), contaminated with the TB agent M. bovis. Conclusions. Disinfecting preparations of DZPT-2 in the concentration of 2.0 % of AI when exposed for 5 h and FAG in the concentration of 2.0 % when exposed for 24 h may be used in the complex of veterinary and sanitary measures to prevent and control TB of farm ani- mals. The possibility of using the polymerase chain reaction as an additional method of estimating tuberculo- cide activity of disinfectants was proven.

scholarly journals Impact of Rapid PCR Influenza Testing on the Rate of Inpatient Admissions During Influenza Season at a Tertiary-Care Center

2020 ◽  
Vol 41 (S1) ◽  
pp. s263-s264
Author(s):  
Jordan Polistico ◽  
Avnish Sandhu ◽  
Teena Chopra ◽  
Erin Goldman ◽  
Jennifer LeRose ◽  
...  
Keyword(s):  
Influenza Season ◽  
Care Center ◽  
Tertiary Care ◽  
The United States ◽  
Turnaround Time ◽  
Care Hospital ◽  
Tertiary Care Center ◽  
Pediatric Hospital ◽  
Rapid Pcr ◽  
The Impact

Background: Influenza causes a high burden of disease in the United States, with an estimate of 960,000 hospitalizations in the 2017–2018 flu season. Traditional flu diagnostic polymerase chain reaction (PCR) tests have a longer (24 hours or more) turnaround time that may lead to an increase in unnecessary inpatient admissions during peak influenza season. A new point-of-care rapid PCR assays, Xpert Flu, is an FDA-approved PCR test that has a significant decrease in turnaround time (2 hours). The present study sought to understand the impact of implementing a new Xpert Flu test on the rate of inpatient admissions. Methods: A retrospective study was conducted to compare rates of inpatient admissions in patients tested with traditional flu PCR during the 2017–2018 flu season and the rapid flu PCR during the 2018–2019 flu season in a tertiary-care center in greater Detroit area. The center has 1 pediatric hospital (hospital A) and 3 adult hospitals (hospital B, C, D). Patients with influenza-like illness who presented to all 4 hospitals during 2 consecutive influenza seasons were analyzed. Results: In total, 20,923 patients were tested with either the rapid flu PCR or the traditional flu PCR. Among these, 14,124 patients (67.2%) were discharged from the emergency department and 6,844 (32.7%) were admitted. There was a significant decrease in inpatient admissions in the traditional flu PCR group compared to the rapid flu PCR group across all hospitals (49.56% vs 26.6% respectively; P < .001). As expected, a significant proportion of influenza testing was performed in the pediatric hospital, 10,513 (50.2%). A greater reduction (30% decrease in the rapid flu PCR group compared to the traditional flu PCR group) was observed in inpatient admissions in the pediatric hospital (Table 1) Conclusions: Rapid molecular influenza testing can significantly decrease inpatient admissions in a busy tertiary-care hospital, which can indirectly lead to improved patient quality with easy bed availability and less time spent in a private room with droplet precautions. Last but not the least, this testing method can certainly lead to lower healthcare costs.Funding: NoneDisclosures: None

Frequency of the delta Phe508 mutation and correlation with XV.2c/KM-19 haplotypes in an American population of cystic fibrosis patients: results of a collaborative study

1990 ◽  
Vol 36 (10) ◽  
pp. 1741-1746 ◽  
Author(s):  
W E Highsmith ◽  
G L Chong ◽  
H T Orr ◽  
T R Perry ◽  
D Schald ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Haplotype Analysis ◽  
Screening Program ◽  
Collaborative Study ◽  
Population Based ◽  
Carrier Status ◽  
Chain Reaction ◽  
Polymerase Chain ◽  
Phenylalanine Residue ◽  
Test Result

Abstract The cystic fibrosis (CF) gene has been recently cloned, and a deletion of 3 basepairs (bp) of DNA was found on most of the CF chromosomes. This deletion leads to the synthesis of a protein that lacks a phenylalanine residue at position 508. Using two polymerase chain reaction protocols to study the frequency of this mutation in a series of 192 CF patients, we found the mutation on 72% of affected chromosomes. We then used this value to calculate the predictive value of a negative test result in a population-based screening program for CF carrier status. Haplotype analysis with the polymorphic markers XV.2c and KM-19 on 239 CF chromosomes revealed that 90.7% of CF chromosomes with the deletion had a single haplotype. This haplotype was also associated with 60.4% of CF chromosomes with unknown mutations. These values can be used to calculate the probability of whether an individual from the general population is a carrier of any CF mutation.

scholarly journals Short antisense oligonucleotides alleviate the pleiotropic toxicity of RNA harboring expanded CGG repeats

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Magdalena Derbis ◽  
Emre Kul ◽  
Daria Niewiadomska ◽  
Michał Sekrecki ◽  
Agnieszka Piasecka ◽  
...  
Keyword(s):  
Motor Behavior ◽  
Neurodegenerative Disorder ◽  
Therapeutic Potential ◽  
Cell Damage ◽  
Fragile X ◽  
Nuclear Proteins ◽  
Mirna Biogenesis ◽  
Loop Formation ◽  
Cgg Repeats ◽  
Initiation Of Translation

AbstractFragile X-associated tremor/ataxia syndrome (FXTAS) is an incurable neurodegenerative disorder caused by expansion of CGG repeats in the FMR1 5’UTR. The RNA containing expanded CGG repeats (rCGGexp) causes cell damage by interaction with complementary DNA, forming R-loop structures, sequestration of nuclear proteins involved in RNA metabolism and initiation of translation of polyglycine-containing protein (FMRpolyG), which forms nuclear insoluble inclusions. Here we show the therapeutic potential of short antisense oligonucleotide steric blockers (ASOs) targeting directly the rCGGexp. In nuclei of FXTAS cells ASOs affect R-loop formation and correct miRNA biogenesis and alternative splicing, indicating that nuclear proteins are released from toxic sequestration. In cytoplasm, ASOs significantly decrease the biosynthesis and accumulation of FMRpolyG. Delivery of ASO into a brain of FXTAS mouse model reduces formation of inclusions, improves motor behavior and corrects gene expression profile with marginal signs of toxicity after a few weeks from a treatment.

scholarly journals Molecular Pathogenesis and Peripheral Monitoring of Adult Fragile X-Associated Syndromes

2021 ◽  
Vol 22 (16) ◽  
pp. 8368
Author(s):  
Luis M. Valor ◽  
Jorge C. Morales ◽  
Irati Hervás-Corpión ◽  
Rosario Marín
Keyword(s):  
Neurodegenerative Disorder ◽  
Late Onset ◽  
Fragile X ◽  
Endocrine System ◽  
Molecular Pathogenesis ◽  
Adult Women ◽  
Adult Men ◽  
Cgg Repeats ◽  
Reproductive Impairment ◽  
Ataxia Syndrome

Abnormal trinucleotide expansions cause rare disorders that compromise quality of life and, in some cases, lifespan. In particular, the expansions of the CGG-repeats stretch at the 5’-UTR of the Fragile X Mental Retardation 1 (FMR1) gene have pleiotropic effects that lead to a variety of Fragile X-associated syndromes: the neurodevelopmental Fragile X syndrome (FXS) in children, the late-onset neurodegenerative disorder Fragile X-associated tremor-ataxia syndrome (FXTAS) that mainly affects adult men, the Fragile X-associated primary ovarian insufficiency (FXPOI) in adult women, and a variety of psychiatric and affective disorders that are under the term of Fragile X-associated neuropsychiatric disorders (FXAND). In this review, we will describe the pathological mechanisms of the adult “gain-of-function” syndromes that are mainly caused by the toxic actions of CGG RNA and FMRpolyG peptide. There have been intensive attempts to identify reliable peripheral biomarkers to assess disease progression and onset of specific pathological traits. Mitochondrial dysfunction, altered miRNA expression, endocrine system failure, and impairment of the GABAergic transmission are some of the affectations that are susceptible to be tracked using peripheral blood for monitoring of the motor, cognitive, psychiatric and reproductive impairment of the CGG-expansion carriers. We provided some illustrative examples from our own cohort. Understanding the association between molecular pathogenesis and biomarkers dynamics will improve effective prognosis and clinical management of CGG-expansion carriers.

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