scholarly journals Rare and widespread: integrating Bayesian MCMC approaches, Sanger sequencing and Hyb‐Seq phylogenomics to reconstruct the origin of the enigmatic Rand Flora genus Camptoloma

2021 ◽  
Author(s):  
Victoria Culshaw ◽  
Tamara Villaverde ◽  
Mario Mairal ◽  
Sanna Olsson ◽  
Isabel Sanmartín
Keyword(s):  
Sanger Sequencing ◽  
Bayesian Mcmc

THE NUCLEAR FACTOR OF HEPATOCYTES 1β (HNF1β)–ASSOCIATED DISEASE. CLINIC, DIAGNOSTIC, TREATMENT (LITERATURE REVIEW AND CLINICAL OBSERVATION)

2019 ◽  
Vol 23 (2) ◽  
pp. 100-108
Author(s):  
S. V. Papizh ◽  
O. R. Piruzieva
Keyword(s):  
Sanger Sequencing ◽  
Clinical Observation ◽  
Liver Enzymes ◽  
Renal Ultrasound ◽  
Nuclear Factor ◽  
Hepatocyte Nuclear Factor ◽  
Renal Hypoplasia ◽  
Unilateral Renal Agenesis ◽  
Elevated Liver Enzymes ◽  
Medullary Nephrocalcinosis

Hepatocyte nuclear factor 1β (HNF1β)-associated disease is a rare autosomal dominant disease caused by various mutations in the HNF1β gene coding the hepatocyte nuclear factor 1β. HNF1β is a transcription factor that is critical for the development of kidney urogenital tract, pancreas, liver, brain, and parathyroid gland. Renal phenotype or HNF1β- nephropathy appeared to be extremely heterogenic: multicystic renal dysplasia, renal hypoplasia, unilateral renal agenesis, horseshoe kidney, atypical familial juvenile hyperuricemic nephropathy, urinary tract malformations and tubular dysfunction. Extrarenal phenotype of HNF1β-associated disease could be maturity-onset diabetes of the young (MODY), pancreatic atrophy and exocrine pancreatic dysfunction, elevated liver enzymes, neonatal cholestasis, congenital abnormalities of the genital tract, hyperparathyroidism, neurological symptoms. The multisystem phenotype makes clinical verification of the diagnosis extremely difficult. In this article, we present a clinical observation of a child with HNF1β – associated disease. The first clinical presentation of HNF1β-associated disease was ultrasound changes in the kidneys (hyperechogenic kidneys?), which were detected by prenatal ultrasonography in pregnancy. Renal ultrasound revealed polycystic kidney disease in the first days of life and bilateral medullary nephrocalcinosis by the age of three. The clinical examination showed a reduced renal function and developed Fanconi syndrome (glycosuria, low molecular proteinuria, hypophosphatemia, aminoaciduria, hyperuricosuria) in the first year of life. Also the child had a non-constant asymptomatic elevation of liver enzymes, hyperparathyroidism, osteoporosis. The diagnosis was confirmed by the results of next generation sequencing which revealed novel heterozygous mutation in exon 4 of the HNF1b gene (chr17: 36091813C>T), p.Cys273Tyr (c.818G>A). The identified mutation was validated by Sanger sequencing. Validation by Sanger sequencing did not reveal a chr17: 36091813C>T mutation in parents, which suggested the appearance of a mutation in the child de novo.

Rare Germline GLMN Variants Identified from Blue Rubber Bleb Nevus Syndrome Might Impact mTOR Signaling

2020 ◽  
Vol 22 (10) ◽  
pp. 675-682 ◽  
Author(s):  
Jie Yin ◽  
Zhongping Qin ◽  
Kai Wu ◽  
Yufei Zhu ◽  
Landian Hu ◽  
...  
Keyword(s):  
Gastrointestinal Tract ◽  
Sanger Sequencing ◽  
Somatic Mutations ◽  
Venous Malformation ◽  
Underlying Disease ◽  
Mtor Signaling ◽  
Functional Effect ◽  
Germline Variants ◽  
Whole Exome

Backgrounds and Objective: Blue rubber bleb nevus syndrome (BRBN) or Bean syndrome is a rare Venous Malformation (VM)-associated disorder, which mostly affects the skin and gastrointestinal tract in early childhood. Somatic mutations in TEK have been identified from BRBN patients; however, the etiology of TEK mutation-negative patients of BRBN need further investigation. Method: Two unrelated sporadic BRBNs and one sporadic VM were firstly screened for any rare nonsilent mutation in TEK by Sanger sequencing and subsequently applied to whole-exome sequencing to identify underlying disease causative variants. Overexpression assay and immunoblotting were used to evaluate the functional effect of the candidate disease causative variants. Results: In the VM case, we identified the known causative somatic mutation in the TEK gene c.2740C>T (p.Leu914Phe). In the BRBN patients, we identified two rare germline variants in GLMN gene c.761C>G (p.Pro254Arg) and c.1630G>T(p.Glu544*). The GLMN-P254R-expressing and GLMN-E544X-expressing HUVECs exhibited increased phosphorylation of mTOR-Ser-2448 in comparison with GLMN-WTexpressing HUVECs in vitro. Conclusion: Our results demonstrated that rare germline variants in GLMN might contribute to the pathogenesis of BRBN. Moreover, abnormal mTOR signaling might be the pathogenesis mechanism underlying the dysfunction of GLMN protein.

scholarly journals Estimating Copy-Number Proportions: The Comeback of Sanger Sequencing

Genes ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 283
Author(s):  
Eyal Seroussi
Keyword(s):  
Copy Number ◽  
Sanger Sequencing ◽  
Cytosine Methylation ◽  
Direct Sequencing ◽  
Information Source ◽  
Gene Copy Number ◽  
Cost Effective ◽  
Gene Copy ◽  
Base Editing ◽  
Recent Developments

Determination of the relative copy numbers of mixed molecular species in nucleic acid samples is often the objective of biological experiments, including Single-Nucleotide Polymorphism (SNP), indel and gene copy-number characterization, and quantification of CRISPR-Cas9 base editing, cytosine methylation, and RNA editing. Standard dye-terminator chromatograms are a widely accessible, cost-effective information source from which copy-number proportions can be inferred. However, the rate of incorporation of dye terminators is dependent on the dye type, the adjacent sequence string, and the secondary structure of the sequenced strand. These variable rates complicate inferences and have driven scientists to resort to complex and costly quantification methods. Because these complex methods introduce their own biases, researchers are rethinking whether rectifying distortions in sequencing trace files and using direct sequencing for quantification will enable comparable accurate assessment. Indeed, recent developments in software tools (e.g., TIDE, ICE, EditR, BEEP and BEAT) indicate that quantification based on direct Sanger sequencing is gaining in scientific acceptance. This commentary reviews the common obstacles in quantification and the latest insights and developments relevant to estimating copy-number proportions based on direct Sanger sequencing, concluding that bidirectional sequencing and sophisticated base calling are the keys to identifying and avoiding sequence distortions.

scholarly journals Machine learning algorithm improved automated droplet classification of ddPCR for detection of BRAF V600E in paraffin-embedded samples

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Gabriel A. Colozza-Gama ◽  
Fabiano Callegari ◽  
Nikola Bešič ◽  
Ana C. de J. Paviza ◽  
Janete M. Cerutti
Keyword(s):  
Machine Learning ◽  
Sanger Sequencing ◽  
Learning Algorithm ◽  
Absolute Quantification ◽  
Braf V600e Mutation ◽  
Braf V600e ◽  
Driver Genes ◽  
Quantitative Classification ◽  
Cancer Driver

AbstractSomatic mutations in cancer driver genes can help diagnosis, prognosis and treatment decisions. Formalin-fixed paraffin-embedded (FFPE) specimen is the main source of DNA for somatic mutation detection. To overcome constraints of DNA isolated from FFPE, we compared pyrosequencing and ddPCR analysis for absolute quantification of BRAF V600E mutation in the DNA extracted from FFPE specimens and compared the results to the qualitative detection information obtained by Sanger Sequencing. Sanger sequencing was able to detect BRAF V600E mutation only when it was present in more than 15% total alleles. Although the sensitivity of ddPCR is higher than that observed for Sanger, it was less consistent than pyrosequencing, likely due to droplet classification bias of FFPE-derived DNA. To address the droplet allocation bias in ddPCR analysis, we have compared different algorithms for automated droplet classification and next correlated these findings with those obtained from pyrosequencing. By examining the addition of non-classifiable droplets (rain) in ddPCR, it was possible to obtain better qualitative classification of droplets and better quantitative classification compared to no rain droplets, when considering pyrosequencing results. Notable, only the Machine learning k-NN algorithm was able to automatically classify the samples, surpassing manual classification based on no-template controls, which shows promise in clinical practice.

scholarly journals Reassessment of Gene-Elusive Familial Dilated Cardiomyopathy Leading to the Discovery of a Homozygous AARS2 Variant—The Importance of Regular Reassessment of Genetic Findings

2021 ◽  
Vol 11 (3) ◽  
pp. 122-128
Author(s):  
Priya Bhardwaj ◽  
Christoffer Rasmus Vissing ◽  
Niels Kjær Stampe ◽  
Kasper Rossing ◽  
Alex Hørby Christensen ◽  
...  
Keyword(s):  
Dilated Cardiomyopathy ◽  
Genetic Screening ◽  
Sanger Sequencing ◽  
Mitochondrial Protein ◽  
Trna Synthetase ◽  
Familial Dilated Cardiomyopathy ◽  
Pathogenic Variants ◽  
Case Summary ◽  
Heterozygous Carriers ◽  
Important Enzyme

Background: AARS2 encodes the mitochondrial protein alanyl-tRNA synthetase 2 (MT-AlaRS), an important enzyme in oxidative phosphorylation. Variants in AARS2 have previously been associated with infantile cardiomyopathy. Case summary: A 4-year-old girl died of infantile-onset dilated cardiomyopathy (DCM) in 1996. Fifteen years later, her 21-year-old brother was diagnosed with DCM and ultimately underwent heart transplantation. Initial sequencing of 15 genes discovered no pathogenic variants in the brother at the time of his diagnosis. However, 9 years later re-screening in an updated screening panel of 129 genes identified a homozygous AARS2 (c.1774C > T) variant. Sanger sequencing of the deceased girl confirmed her to be homozygous for the AARS2 variant, while both parents and a third sibling were all found to be unaffected heterozygous carriers of the AARS2 variant. Discussion: This report underlines the importance of repeated and extended genetic screening of elusive families with suspected hereditary cardiomyopathies, as our knowledge of disease-causing mutations continuously grows. Although identification of the genetic etiology in the reported family would not have changed the clinical management, the genetic finding allows genetic counselling and holds substantial value in identifying at-risk relatives.

scholarly journals NAPG mutation in family members with hereditary hemorrhagic telangiectasia in China

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yu Xu ◽  
Yong-Biao Zhang ◽  
Li-Jun Liang ◽  
Jia-Li Tian ◽  
Jin-Ming Lin ◽  
...  
Keyword(s):  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Hereditary Hemorrhagic Telangiectasia ◽  
Sanger Sequencing ◽  
Conformational Stability ◽  
Sequencing Analysis ◽  
Large Pedigree ◽  
Whole Exome ◽  
Variant Filtering ◽  
Genetic Contributions

Abstract Background Hereditary hemorrhagic telangiectasia (HHT) is a disease characterized by arteriovenous malformations in the skin and mucous membranes. We enrolled a large pedigree comprising 32 living members, and screened for mutations responsible for HHT. Methods We performed whole-exome sequencing to identify novel mutations in the pedigree after excluding three previously reported HHT-related genes using Sanger sequencing. We then performed in silico functional analysis of candidate mutations that were obtained using a variant filtering strategy to identify mutations responsible for HHT. Results After screening the HHT-related genes, activin A receptor-like type 1 (ACVRL1), endoglin (ENG), and SMAD family member 4 (SMAD4), we did not detect any co-segregated mutations in this pedigree. Whole-exome sequencing analysis of 7 members and Sanger sequencing analysis of 16 additional members identified a mutation (c.784A > G) in the NSF attachment protein gamma (NAPG) gene that co-segregated with the disease. Functional prediction showed that the mutation was deleterious and might change the conformational stability of the NAPG protein. Conclusions NAPG c.784A > G may potentially lead to HHT. These results expand the current understanding of the genetic contributions to HHT pathogenesis.

scholarly journals HIV-1 Drug Resistance Genotyping in Resource Limited Settings: Current and Future Perspectives in Sequencing Technologies

Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1125
Author(s):  
Sontaga Manyana ◽  
Lilishia Gounder ◽  
Melendhran Pillay ◽  
Justen Manasa ◽  
Kogieleum Naidoo ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Sanger Sequencing ◽  
Clinical Diagnostics ◽  
Treatment Programs ◽  
People Living With Hiv ◽  
Resource Limited Settings ◽  
Gold Standard Method ◽  
Sequencing Technologies ◽  
Resource Limited ◽  
Hiv 1

Affordable, sensitive, and scalable technologies are needed for monitoring antiretroviral treatment (ART) success with the goal of eradicating HIV-1 infection. This review discusses use of Sanger sequencing and next generation sequencing (NGS) methods for HIV-1 drug resistance (HIVDR) genotyping, focusing on their use in resource limited settings (RLS). Sanger sequencing remains the gold-standard method for detecting HIVDR mutations of clinical relevance but is mainly limited by high sequencing costs and low-throughput. NGS is becoming a more common sequencing method, with the ability to detect low-abundance drug-resistant variants and reduce per sample costs through sample pooling and massive parallel sequencing. However, use of NGS in RLS is mainly limited by infrastructure costs. Given these shortcomings, our review discusses sequencing technologies for HIVDR genotyping, focusing on common in-house and commercial assays, challenges with Sanger sequencing in keeping up with changes in HIV-1 treatment programs, as well as challenges with NGS that limit its implementation in RLS and in clinical diagnostics. We further discuss knowledge gaps and offer recommendations on how to overcome existing barriers for implementing HIVDR genotyping in RLS, to make informed clinical decisions that improve quality of life for people living with HIV.

scholarly journals An FGA Frameshift Variant Associated with Afibrinogenemia in Dachshunds

Genes ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 1065
Author(s):  
Reinhard Mischke ◽  
Julia Metzger ◽  
Ottmar Distl
Keyword(s):  
Protein Sequence ◽  
Sanger Sequencing ◽  
Selective Breeding ◽  
Genome Wide Association Study ◽  
Frameshift Mutation ◽  
Homozygosity Mapping ◽  
Genomic Region ◽  
Severe Bleeding ◽  
Genome Wide ◽  
A Genome

Congenital fibrinogen disorders are very rare in dogs. Cases of afibrinogenemia have been reported in Bernese Mountain, Bichon Frise, Cocker Spaniel, Collie, Lhasa Apso, Viszla, and St. Bernard dogs. In the present study, we examined four miniature wire-haired Dachshunds with afibrinogenemia and ascertained their pedigree. Homozygosity mapping and a genome-wide association study identified a candidate genomic region at 50,188,932–64,187,680 bp on CFA15 harboring FGB (fibrinogen beta chain), FGA (fibrinogen alpha chain), and FGG (fibrinogen gamma-B chain). Sanger sequencing of all three fibrinogen genes in two cases and validation of the FGA-associated mutation (FGA:g.6296delT, NC_006597.3:g.52240694delA, rs1152388481) in pedigree members showed a perfect co-segregation with afibrinogenemia-affected phenotypes, obligate carriers, and healthy animals. In addition, the rs1152388481 variant was validated in 393 Dachshunds and samples from 33 other dog breeds. The rs1152388481 variant is predicted to modify the protein sequence of both FGA transcripts (FGA201:p.Ile486Met and FGA-202:p.Ile555Met) leading to proteins truncated by 306 amino acids. The present data provide evidence for a novel FGA truncating frameshift mutation that is very likely to explain the cases of severe bleeding due to afibrinogenemia in a Dachshund family. This mutation has already been spread in Dachshunds through carriers before cases were ascertained. Genetic testing allows selective breeding to prevent afibrinogenemia-affected puppies in the future.

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