scholarly journals Genetics and Genomics Approaches for Diagnosis and Research Into Hereditary Anemias

2020 ◽  
Vol 11 ◽  
Author(s):  
Roberta Russo ◽  
Roberta Marra ◽  
Barbara Eleni Rosato ◽  
Achille Iolascon ◽  
Immacolata Andolfo

The hereditary anemias are a relatively heterogeneous set of disorders that can show wide clinical and genetic heterogeneity, which often hampers correct clinical diagnosis. The classical diagnostic workflow for these conditions generally used to start with analysis of the family and personal histories, followed by biochemical and morphological evaluations, and ending with genetic testing. However, the diagnostic framework has changed more recently, and genetic testing is now a suitable approach for differential diagnosis of these patients. There are several approaches to this genetic testing, the choice of which depends on phenotyping, genetic heterogeneity, and gene size. For patients who show complete phenotyping, single-gene testing remains recommended. However, genetic analysis now includes next-generation sequencing, which is generally based on custom-designed targeting panels and whole-exome sequencing. The use of next-generation sequencing also allows the identification of new causative genes, and of polygenic conditions and genetic factors that modify disease severity of hereditary anemias. In the research field, whole-genome sequencing is useful for the identification of non-coding causative mutations, which might account for the disruption of transcriptional factor occupancy sites and cis-regulatory elements. Moreover, advances in high-throughput sequencing techniques have now resulted in the identification of genome-wide profiling of the chromatin structures known as the topologically associating domains. These represent a recurrent disease mechanism that exposes genes to inappropriate regulatory elements, causing errors in gene expression. This review focuses on the challenges of diagnosis and research into hereditary anemias, with indications of both the advantages and disadvantages. Finally, we consider the future perspectives for the use of next-generation sequencing technologies in this era of precision medicine.

Genes ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 429 ◽  
Author(s):  
Daniela Barros-Silva ◽  
C. Marques ◽  
Rui Henrique ◽  
Carmen Jerónimo

DNA methylation is an epigenetic modification that plays a pivotal role in regulating gene expression and, consequently, influences a wide variety of biological processes and diseases. The advances in next-generation sequencing technologies allow for genome-wide profiling of methyl marks both at a single-nucleotide and at a single-cell resolution. These profiling approaches vary in many aspects, such as DNA input, resolution, coverage, and bioinformatics analysis. Thus, the selection of the most feasible method according with the project’s purpose requires in-depth knowledge of those techniques. Currently, high-throughput sequencing techniques are intensively used in epigenomics profiling, which ultimately aims to find novel biomarkers for detection, diagnosis prognosis, and prediction of response to therapy, as well as to discover new targets for personalized treatments. Here, we present, in brief, a portrayal of next-generation sequencing methodologies’ evolution for profiling DNA methylation, highlighting its potential for translational medicine and presenting significant findings in several diseases.


2020 ◽  
Author(s):  
Huaiyu Gu ◽  
Zhen Zhang ◽  
Yi-shuang Xiao ◽  
Ru Shen ◽  
Hong-chao Jiang ◽  
...  

Abstract Background: Retinoblastoma is a rare intraocular malignancy and typically initiated by inactivating biallelic mutations of RB1 gene. Each year, ~8,000 children worldwide are diagnosed for retinoblastoma. In high-income countries, patient survival is over 95% while low-income countries is ~30%.If disease is diagnosed early and treated in centers specializing in retinoblastoma, the survival might exceed 95% and many eyes could be safely treated and support a lifetime of good vision. In China, approximate 1,100 newly diagnosed cases are expected annually and 28 hospitals covering 25 provinces established centers classified by expertise and resources for better treatment options and follow-up. Comparing with other province of eastern China, Yunnan province is remote geographically. This might result that healthcare staff have low awareness of the role of genetic testing in management and screening in families.Methods: The patients with retinoblastoma were selected in Yunnan. DNA from blood was used for targeted gene sequencing. Then, an in-house bioinformatics pipeline was done to detect both single nucleotide variants and small insertions/deletions. The pathogenic mutations were identified and further confirmed by conventional methods and cosegregation in families.Results: Using our approach, targeted next generation sequencing was used to detect the mutation of these 12 probands. Bioinformatic predictions showed that nine mutations were found in our study and four were novel pathogenic variants in these nine mutations.Conclusions: It’s the first report to describe RB1 mutations in Yunnan children with retinoblastoma. This study would improve role of genetic testing for management and family screening.


2021 ◽  
Vol 21 ◽  
Author(s):  
Leonardo Ulivi ◽  
Mirco Cosottini ◽  
Gianmichele Migaleddu ◽  
Giovanni Orlandi ◽  
Nicola Giannini ◽  
...  

: Monogenic cerebral small vessel diseases are a topic of growing interest, as several genes responsible have been recently described and new sequencing techniques such as Next generation sequencing are available. Brain imaging is a key exam in these diseases. First, since it is often the first exam performed, an MRI is key in selecting patients for genetic testing and for interpreting Next generation sequencing reports. In addition, neuroimaging can be helpful in describing the underlying pathological mechanisms involved in cerebral small vessel disease. With this review, we aim to provide Neurologists and Stroke physicians with an up-to date overview of the current neuroimaging knowledge on monogenic small vessel diseases.


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