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Molecular Diagnosis and Genetic Counseling of Cystic Fibrosis and Related Disorders: New Challenges.Genes Jun 2020Identification of the cystic fibrosis transmembrane conductance regulator gene and its numerous variants opened the way to fantastic breakthroughs in diagnosis,... (Review)
Review
Identification of the cystic fibrosis transmembrane conductance regulator gene and its numerous variants opened the way to fantastic breakthroughs in diagnosis, research and treatment of cystic fibrosis (CF). The current and future challenges of molecular diagnosis of CF and CFTR-related disorders and of genetic counseling are here reviewed. Technological advances have enabled to make a diagnosis of CF with a sensitivity of 99% by using next generation sequencing in a single step. The detection of heretofore unidentified variants and ethnic-specific variants remains challenging, especially for newborn screening (NBS), CF carrier testing and genotype-guided therapy. Among the criteria for assessing the impact of variants, population genetics data are insufficiently taken into account and the penetrance of CF associated with variants remains poorly known. The huge diversity of diagnostic and genetic counseling indications for studies makes assessment of variant disease-liability critical. This is especially discussed in the perspective of wide genome analyses for NBS and CF carrier screening in the general population, as future challenges.
Topics: Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Genetic Counseling; Genotype; Humans; Infant, Newborn; Neonatal Screening; Pathology, Molecular; Penetrance
PubMed: 32512765
DOI: 10.3390/genes11060619 -
JAMA Nov 2014Clinical whole-exome sequencing is increasingly used for diagnostic evaluation of patients with suspected genetic disorders. (Observational Study)
Observational Study
IMPORTANCE
Clinical whole-exome sequencing is increasingly used for diagnostic evaluation of patients with suspected genetic disorders.
OBJECTIVE
To perform clinical whole-exome sequencing and report (1) the rate of molecular diagnosis among phenotypic groups, (2) the spectrum of genetic alterations contributing to disease, and (3) the prevalence of medically actionable incidental findings such as FBN1 mutations causing Marfan syndrome.
DESIGN, SETTING, AND PATIENTS
Observational study of 2000 consecutive patients with clinical whole-exome sequencing analyzed between June 2012 and August 2014. Whole-exome sequencing tests were performed at a clinical genetics laboratory in the United States. Results were reported by clinical molecular geneticists certified by the American Board of Medical Genetics and Genomics. Tests were ordered by the patient's physician. The patients were primarily pediatric (1756 [88%]; mean age, 6 years; 888 females [44%], 1101 males [55%], and 11 fetuses [1% gender unknown]), demonstrating diverse clinical manifestations most often including nervous system dysfunction such as developmental delay.
MAIN OUTCOMES AND MEASURES
Whole-exome sequencing diagnosis rate overall and by phenotypic category, mode of inheritance, spectrum of genetic events, and reporting of incidental findings.
RESULTS
A molecular diagnosis was reported for 504 patients (25.2%) with 58% of the diagnostic mutations not previously reported. Molecular diagnosis rates for each phenotypic category were 143/526 (27.2%; 95% CI, 23.5%-31.2%) for the neurological group, 282/1147 (24.6%; 95% CI, 22.1%-27.2%) for the neurological plus other organ systems group, 30/83 (36.1%; 95% CI, 26.1%-47.5%) for the specific neurological group, and 49/244 (20.1%; 95% CI, 15.6%-25.8%) for the nonneurological group. The Mendelian disease patterns of the 527 molecular diagnoses included 280 (53.1%) autosomal dominant, 181 (34.3%) autosomal recessive (including 5 with uniparental disomy), 65 (12.3%) X-linked, and 1 (0.2%) mitochondrial. Of 504 patients with a molecular diagnosis, 23 (4.6%) had blended phenotypes resulting from 2 single gene defects. About 30% of the positive cases harbored mutations in disease genes reported since 2011. There were 95 medically actionable incidental findings in genes unrelated to the phenotype but with immediate implications for management in 92 patients (4.6%), including 59 patients (3%) with mutations in genes recommended for reporting by the American College of Medical Genetics and Genomics.
CONCLUSIONS AND RELEVANCE
Whole-exome sequencing provided a potential molecular diagnosis for 25% of a large cohort of patients referred for evaluation of suspected genetic conditions, including detection of rare genetic events and new mutations contributing to disease. The yield of whole-exome sequencing may offer advantages over traditional molecular diagnostic approaches in certain patients.
Topics: Adolescent; Adult; Child; Child, Preschool; Exome; Female; Fetus; Genetic Diseases, Inborn; Genetic Testing; Genomics; Humans; Incidental Findings; Infant; Infant, Newborn; Male; Molecular Diagnostic Techniques; Mutation; Phenotype; Referral and Consultation; Sequence Analysis, DNA
PubMed: 25326635
DOI: 10.1001/jama.2014.14601 -
Andrology Jan 2014The molecular diagnosis of Y-chromosomal microdeletions is a common routine genetic test which is part of the diagnostic workup of azoospermic and severe oligozoospermic... (Review)
Review
The molecular diagnosis of Y-chromosomal microdeletions is a common routine genetic test which is part of the diagnostic workup of azoospermic and severe oligozoospermic men. Since 1999, the European Academy of Andrology (EAA) and the European Molecular Genetics Quality Network (EMQN) have been actively involved in supporting the improvement of the quality of the diagnostic assays by publication of the laboratory guidelines for molecular diagnosis of Y-chromosomal microdeletions and by offering external quality assessment trials. The present revision of the 2004 laboratory guidelines summarizes all the clinical novelties related to the Y chromosome (classic, partial and gene-specific deletions, genotype-phenotype correlations, methodological issues) and provides an update on the results of the quality control programme. These aspects also reflect the consensus of a large group of specialists present at a round table session during the recent Florence-Utah-Symposium on 'Genetics of male infertility' (Florence, 19-21 September, 2013). During the last 10 years the gr/gr deletion has been demonstrated as a significant risk factor for impaired sperm production. However, the screening for this deletion type in the routine diagnostic setting is still a debated issue among experts. The original basic protocol based on two multiplex polymerase chain reactions remains fully valid and appropriate for accurate diagnosis of complete AZF deletions and it requires only a minor modification in populations with a specific Y chromosome background. However, in light of novel data on genotype-phenotype correlations, the extension analysis for the AZFa and AZFb deletions is now routinely recommended. Novel methods and kits with excessively high number of markers do not improve the sensitivity of the test, may even complicate the interpretation of the results and are not recommended. Annual participation in an external quality control programme is strongly encouraged. The 12-year experience with the EMQN/EAA scheme has shown a steep decline in diagnostic (genotyping) error rate and a simultaneous improvement on reporting practice.
Topics: Humans; Male; Azoospermia; Chromosome Deletion; Chromosomes, Human, Y; Genetic Counseling; Genetic Testing; Genotype; Genotyping Techniques; Infertility, Male; Molecular Diagnostic Techniques; Oligospermia; Sex Chromosome Aberrations; Sex Chromosome Disorders of Sex Development
PubMed: 24357628
DOI: 10.1111/j.2047-2927.2013.00173.x -
International Journal of Molecular... 2012Multiplex Ligation-dependent Probe Amplification (MLPA) assay is a recently developed technique able to evidence variations in the copy number of several human genes.... (Review)
Review
Multiplex Ligation-dependent Probe Amplification (MLPA) assay is a recently developed technique able to evidence variations in the copy number of several human genes. Due to this ability, MLPA can be used in the molecular diagnosis of several genetic diseases whose pathogenesis is related to the presence of deletions or duplications of specific genes. Moreover, MLPA assay can also be used in the molecular diagnosis of genetic diseases characterized by the presence of abnormal DNA methylation. Due to the large number of genes that can be analyzed by a single technique, MLPA assay represents the gold standard for molecular analysis of all pathologies derived from the presence of gene copy number variation. In this review, the main applications of the MLPA technique for the molecular diagnosis of human diseases are described.
Topics: DNA Copy Number Variations; DNA Methylation; Female; Gene Deletion; Gene Dosage; Gene Duplication; Genetic Diseases, Inborn; Humans; Male; Molecular Diagnostic Techniques; Multiplex Polymerase Chain Reaction; Mutation; Neoplasms; Neuromuscular Diseases; Pregnancy; Prenatal Diagnosis
PubMed: 22489151
DOI: 10.3390/ijms13033245 -
Frontiers in Neurology 2021Advances in next-generation sequencing (NGS) facilitate the diagnosis of genetic disorders. To evaluate its use for the molecular diagnosis of inherited optic neuropathy...
Advances in next-generation sequencing (NGS) facilitate the diagnosis of genetic disorders. To evaluate its use for the molecular diagnosis of inherited optic neuropathy (ION), a blinding disease caused by the degeneration of retinal ganglion cells, we performed genetic analysis using targeted NGS of 22 already known and candidate genes in a cohort of 1,102 affected individuals. The panel design, library preparation, and sequencing reactions were performed using the Ion AmpliSeq technology. Pathogenic variants were detected in 16 genes in 245 patients (22%), including 186 (17%) and 59 (5%) dominant and recessive cases, respectively. Results confirmed that variants are responsible for the majority of dominant IONs, whereas and variants are also frequently involved in both dominant and recessive forms of ION. All pathogenic variants were found in genes encoding proteins involved in the mitochondrial function, highlighting the importance of mitochondria in the survival of retinal ganglion cells.
PubMed: 33841295
DOI: 10.3389/fneur.2021.602979 -
Journal of Maxillofacial and Oral... Sep 2021In this article, we provide a gestalt idea about NGS technologies and their applications in cancer research and molecular diagnosis. (Review)
Review
OBJECTIVE
In this article, we provide a gestalt idea about NGS technologies and their applications in cancer research and molecular diagnosis.
BACKGROUND
Next-generation sequencing (NGS) advancements like DNA sequencing and RNA sequencing allow uncovering of genomic, transcriptomic, and epigenomic scenes of individual malignant growths. An assortment of genomic abnormalities can be screened at the same time, for example common and uncommon variations, auxiliary variations like insertions and deletions, copy-number variation, and fusion transcripts.
CONCLUSION
NGS innovations together with bioinformatics investigation, which extend our insight, are progressively used to analyze multiple genes in a cost-effective way and have been applied in examining clinical cancer samples and offering NGS-based molecular diagnosis.
APPLICATION
NGS is progressively significant as a device for the diagnosis of cancers.
PubMed: 34408360
DOI: 10.1007/s12663-020-01462-4 -
Deutsches Arzteblatt International Mar 2019
Topics: Child; Exome; Genetic Testing; Humans; Mutation
PubMed: 31056084
DOI: 10.3238/arztebl.2019.0195 -
Journal of Fungi (Basel, Switzerland) Dec 2022Diagnosis of endemic mycoses is still challenging. The moderated availability of reliable diagnostic methods, the lack of clinical suspicion out of endemic areas and the... (Review)
Review
Diagnosis of endemic mycoses is still challenging. The moderated availability of reliable diagnostic methods, the lack of clinical suspicion out of endemic areas and the limitations of conventional techniques result in a late diagnosis that, in turn, delays the implementation of the correct antifungal therapy. In recent years, molecular methods have emerged as promising tools for the rapid diagnosis of endemic mycoses. However, the absence of a consensus among laboratories and the reduced availability of commercial tests compromises the diagnostic effectiveness of these methods. In this review, we summarize the advantages and limitations of molecular methods for the diagnosis of endemic mycoses.
PubMed: 36675880
DOI: 10.3390/jof9010059 -
Chonnam Medical Journal Jan 2018Tuberculosis (TB) is one of the leading causes of adult death in the Asia-Pacific Region, including Indonesia. As an infectious disease caused by (MTB), TB remains a... (Review)
Review
Tuberculosis (TB) is one of the leading causes of adult death in the Asia-Pacific Region, including Indonesia. As an infectious disease caused by (MTB), TB remains a major public health issue especially in developing nations due to the lack of adequate diagnostic testing facilities. Diagnosis of TB has entered an era of molecular detection that provides faster and more cost-effective methods to diagnose and confirm drug resistance in TB cases, meanwhile, diagnosis by conventional culture systems requires several weeks. New advances in the molecular detection of TB, including the faster and simpler nucleic acid amplification test (NAAT) and whole-genome sequencing (WGS), have resulted in a shorter time for diagnosis and, therefore, faster TB treatments. In this review, we explored the current findings on molecular diagnosis of TB and drug-resistant TB to see how this advancement could be integrated into public health systems in order to control TB.
PubMed: 29399559
DOI: 10.4068/cmj.2018.54.1.1 -
Future Microbiology 2016A 10-year experience of our automated molecular diagnostic platform that carries out 91 different real-time PCR is described. Progresses and future perspectives in... (Review)
Review
A 10-year experience of our automated molecular diagnostic platform that carries out 91 different real-time PCR is described. Progresses and future perspectives in molecular diagnostic microbiology are reviewed: why automation is important; how our platform was implemented; how homemade PCRs were developed; the advantages/disadvantages of homemade PCRs, including the critical aspects of troubleshooting and the need to further reduce the turnaround time for specific samples, at least for defined clinical settings such as emergencies. The future of molecular diagnosis depends on automation, and in a novel perspective, it is time now to fully acknowledge the true contribution of molecular diagnostic and to reconsider the indication for PCR, by also using these tests as first-line assays.
Topics: Automation; Humans; Infections; Molecular Diagnostic Techniques; Real-Time Polymerase Chain Reaction; Reproducibility of Results; Sensitivity and Specificity; Time Factors
PubMed: 27028061
DOI: 10.2217/fmb.15.152