MALDI-TOF-MS Assay to Detect the Hemizygous 22q11.2 Deletion in DNA from Dried Blood Spots

Abstract BACKGROUND A hemizygous deletion of 1.5–3 Mb in 22q11.2 causes a distinct clinical syndrome with variable congenital defects. Current diagnostic methods use fluorescent in situ hybridization (FISH) or comparative genomic hybridization by microarray to detect the deletion. Neither method is suitable for newborn screening (NBS), since they cannot be performed on dried blood spots (DBS). We developed a MALDI-TOF-MS assay that uses DBS to measure the hemizygous deletion of UFD1L, located within the 22q11.2 region. METHODS We used DBS from 54 affected patients, previously tested by FISH or microarray, and 100 cord blood samples to evaluate the performance of the MALDI-TOF-MS assay. With a single primer pair, a 97-base oligonucleotide within UFD1L was amplified, as was a sequence on chromosome 18 that differs by 2 nucleotides. A multiplexed, single-base extension reaction created allele-specific products for MALDI-TOF-MS detection. The products were spotted onto a silicon chip, and the height of the spectral peaks identified the relative amounts of target and reference gene. RESULTS The median ratio of the spectral peak for each UFD1L target:reference base was 0.96 and 0.99 for controls, compared with 0.35 and 0.53 for 22q11 deletion syndrome patients. There was 100% concordance between FISH/microarray and MALDI-TOF-MS in all patients with 22q11.2 deletion syndrome. CONCLUSIONS This method can be reliably performed with DBS and is suitable for high sample throughput. This assay may be considered for use in population-based NBS for 22q11.2 deletion.

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A Novel Method for Newborn Screening for 22q11.2 Deletion Syndrome Using Dried Blood Spots

Journal of Allergy and Clinical Immunology ◽

10.1016/j.jaci.2012.12.1160 ◽

2013 ◽

Vol 131 (2) ◽

pp. AB139

Author(s):

Lisa J. Kobrynski

Keyword(s):

Newborn Screening ◽

22Q11.2 Deletion Syndrome ◽

Dried Blood Spots ◽

Deletion Syndrome ◽

22Q11.2 Deletion ◽

Blood Spots ◽

Novel Method

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MALDI-TOF Mass Spectroscopy Applications in Clinical Microbiology

Advances in Pharmacological and Pharmaceutical Sciences ◽

10.1155/2021/9928238 ◽

2021 ◽

Vol 2021 ◽

pp. 1-8

Author(s):

Maryam Alizadeh ◽

Leila Yousefi ◽

Farzaneh Pakdel ◽

Reza Ghotaslou ◽

Mohammad Ahangarzadeh Rezaee ◽

...

Keyword(s):

Mass Spectrometry ◽

Bacterial Infections ◽

Bacterial Species ◽

Diagnostic Methods ◽

Ionization Mass ◽

Two Dimensional Gel Electrophoresis ◽

Maldi Tof Ms ◽

Maldi Tof ◽

Comprehensive Information ◽

Tof Ms

There is a range of proteomics methods to spot and analyze bacterial protein contents such as liquid chromatography-mass spectrometry (LC-MS), two-dimensional gel electrophoresis, and matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF MS), which give comprehensive information about the microorganisms that may be helpful within the diagnosis and coverings of infections. Microorganism identification by mass spectrometry is predicted on identifying a characteristic spectrum of every species so matched with an outsized database within the instrument. MALDI-TOF MS is one of the diagnostic methods, which is a straightforward, quick, and precise technique, and is employed in microbial diagnostic laboratories these days and may replace other diagnostic methods. This method identifies various microorganisms such as bacteria, fungi, parasites, and viruses, which supply comprehensive information. One of the MALDI-TOF MS’s crucial applications is bacteriology, which helps identify bacterial species, identify toxins, and study bacterial antibiotic resistance. By knowing these cases, we will act more effectively against bacterial infections.

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TU64. UNTARGETED METABOLIC PROFILING IN DRIED BLOOD SPOTS REVEALS METABOLIC FINGERPRINT FOR 22Q11.2 DELETION SYNDROME

European Neuropsychopharmacology ◽

10.1016/j.euroneuro.2021.08.067 ◽

2021 ◽

Vol 51 ◽

pp. e130

Author(s):

Janneke Zinkstok ◽

Dorinde Korteling ◽

Ania Fiksinski ◽

Judith Jans ◽

Nanda Verhoeven ◽

...

Keyword(s):

Metabolic Profiling ◽

22Q11.2 Deletion Syndrome ◽

Dried Blood Spots ◽

Deletion Syndrome ◽

22Q11.2 Deletion ◽

Blood Spots ◽

Metabolic Fingerprint

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Accuracy of matrix-assisted LASER desorption ionization–time of flight mass spectrometry for identification of Candida

Bioscience Reports ◽

10.1042/bsr20190859 ◽

2019 ◽

Vol 39 (10) ◽

Cited By ~ 1

Author(s):

Tian-Ao Xie ◽

Ye-Ling Liu ◽

Chuan Liang ◽

Yuan-Yuan Huang ◽

Jin-Wei Li ◽

...

Keyword(s):

Pooled Analysis ◽

Diagnostic Methods ◽

Identification Accuracy ◽

Cochrane Library ◽

Original Research ◽

Correct Identification ◽

Maldi Tof Ms ◽

Maldi Tof ◽

Flight Mass Spectrometry ◽

Tof Ms

Abstract Background: Candida is a fungus that causes various types of candidemia, which is the fourth major infectious disease of the blood system. MALDI-TOF-MS is a simple and rapid detection instrument. The aim of the present study was to verify the accuracy of MALDI-TOF-MS in detecting Candida. Method: A pooled analysis of articles on MALDI-TOF-MS for diagnosis of candidemia was performed. The quality of original research was assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) guidelines. Stata 12.0 software was used to merge the correct identification rates of Candida and Candida subspecies and obtain pooled sensitivity and specificity of the diagnostic methods. Heterogeneity was found in the subgroup analysis of the included articles. Hence, we explored the factors causing the heterogeneity and its impact on the overall situation. Sensitivity analysis was used to examine the effect of Candida level on total response. Egger’s test was used to evaluate the publication bias of the included articles. Results: A total of 16 articles in Pubmed, 79 articles in Embase, 1 article in Cochrane Library, 30 articles in Web of Science and 3 from other sources were identified, of which 10 articles were included based on the inclusion and exclusion criteria. The overall identification accuracy was 100%. Conclusion: The accuracy of MALDI-TOF-MS for the identification of Candida was 100%. Further research is necessary to determine whether MALDI-TOF-MS can be used as a clinical diagnostic standard for the identification of Candida.

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Application of MALDI-TOF MS for identification of clinical isolates of bacteria from humans and animals

Diagnostyka Laboratoryjna ◽

10.5604/01.3001.0004.1302 ◽

2015 ◽

Vol 51 (1) ◽

pp. 23-30

Author(s):

Urszula Kosikowska ◽

Dagmara Stępień-Pyśniak ◽

Dorota Pietras-Ożga ◽

Sylwia Andrzejczuk ◽

Marek Juda ◽

...

Keyword(s):

Protein Profile ◽

Biochemical Properties ◽

Breeding Birds ◽

Diagnostic Methods ◽

Maldi Tof Ms ◽

Biochemical Methods ◽

Maldi Tof ◽

Flight Mass Spectrometry ◽

Human Pathology ◽

Tof Ms

Routinely used diagnostic methods are insufficient to identify the microorganisms with unusual biochemical properties or less commonly occurring, including zoonotic microorganisms. During our study the possibility of identification of different bacteria isolated from humans and from breeding birds using MALDI-TOF MS (Matrix Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry) and biochemical methods was compared. The material for the study were 6 reference strains from ATCC, 30 isolates selected from healthy people (throat and nasal swabs) and 16 isolates selected from birds breeding (throat swabs from the vicinity of throat of asymptomatic birds and biopsies from the heart of the dead birds). Isolates were identified based on their biochemical properties (biochemical microtests and panels for biochemical analyzer Vitek 2) or based on a protein profile using MALDI-TOF MS technique. Biochemical methods were sufficient to identify the most common and relevant to human pathology pathogens such as e.g. Escherichia coli and Staphylococcus aureus; these results were consistent with the data obtained using MALDI-TOF MS. Identification of less common bacteria required the use of MALDI-TOF MS, because some bacteria isolated from humans or breeding birds could not be classified by their biochemical properties. The biggest differences were observed in the case of bacteria from the Pasteurellaceae family, which on the basis of biochemical properties were classified mainly as Haemophilus spp., whereas in accordance to the results obtained from the protein profile as Avibacterium endocarditidis. Identification of microorganisms using MALDI-TOF MS has proved to be more useful in the diagnosis of micro-organisms rarely isolated or problematic in routine diagnostics.

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