scholarly journals Molecular genetic testing strategies used in diagnostic flow for hereditary endocrine tumour syndromes

Endocrine ◽  
2021 ◽  
Vol 71 (3) ◽  
pp. 641-652
Author(s):  
Henriett Butz ◽  
Jo Blair ◽  
Attila Patócs

Abstract Introduction Although current guidelines prefer the use of targeted testing or small-scale gene panels for identification of genetic susceptibility of hereditary endocrine tumour syndromes, next generation sequencing based strategies have been widely introduced into every day clinical practice. The application of next generation sequencing allows rapid testing of multiple genes in a cost effective manner. Increasing knowledge about these techniques and the demand from health care providers and society, shift the molecular genetic testing towards using high-throughput approaches. Purpose In this expert opinion, the authors consider the molecular diagnostic workflow step by step, evaluating options and challenges of gathering family information, pre- and post-test genetic counselling, technical and bioinformatical analysis related issues and difficulties in clinical interpretation focusing on molecular genetic testing of hereditary endocrine tumour syndromes. Result and conclusion Considering all these factors, a diagnostic genetic workflow is also proposed for selection of the best approach for testing of patients with hereditary genetic tumour syndromes in order to minimalize difficult interpretation, unwanted patient anxiety, unnecessary medical interventions and cost. There are potential benefits of utilizing high throughput approaches however, important limitations have to be considered and should discussed towards the clinicians and patients.

2017 ◽  
Vol 141 (4) ◽  
pp. 564-568 ◽  
Author(s):  
Jerzy Lasota ◽  
Artur Kowalik ◽  
Anna Felisiak-Golabek ◽  
Shingo Inaguma ◽  
Zeng-Feng Wang ◽  
...  

Context.— NRAS is a member of the RAS family oncoproteins implicated in cancer. Gain-of-function NRAS mutations were reported in a subset of colorectal cancers. These mutations occur at codons 12, 13, and 61 and are detected by molecular genetic testing. Recently, an antibody (clone SP174) became available to immunohistochemically pinpoint NRAS Q61R mutant protein. In malignant melanoma, NRAS Q61R mutant–specific immunohistochemistry was shown to be a valuable supplement to traditional genetic testing. Objective.— To evaluate the significance of NRAS Q61R mutant–specific immunohistochemistry in a cohort of colorectal carcinomas. Design.— A total of 1185 colorectal carcinomas were immunohistochemically evaluated with SP174 antibody. NRAS Q61R mutant–specific immunohistochemistry was validated by molecular genetic testing including Sanger sequencing, quantitative polymerase chain reaction (qPCR), and next-generation sequencing. Results.— Twelve tumors showed strong SP174 immunoreactivity. Sanger sequencing detected an identical c.182A>G substitution, causing NRAS Q61R mutation at the protein level, only in 8 SP174-positive cases. These results were confirmed by qPCR study. Subsequently, NRAS wild-type tumors with strong SP174 staining were evaluated by next-generation sequencing and revealed KRAS c.182A>G substitutions predicted to cause KRAS Q61R mutation. Review of colorectal carcinomas with known KRAS and NRAS genotype revealed that none of 62 wild-type tumors or 47 mutants other than Q61R were SP174 positive. Conclusion.— SP174 immunohistochemistry allows sensitive detection of NRAS and KRAS Q61R mutants. However, molecular genetic testing is necessary to determine specifically which RAS gene is mutated.


2020 ◽  
Vol 63 (6) ◽  
pp. 195-202 ◽  
Author(s):  
Ji Yoon Han ◽  
In Goo Lee

Developments in next-generation sequencing (NGS) techogies have assisted in clarifying the diagnosis and treatment of developmental delay/intellectual disability (DD/ID) via molecular genetic testing. Advances in DNA sequencing technology have not only allowed the evolution of targeted panels but also, and more currently enabled genome-wide analyses to progress from research era to clinical practice. Broad acceptance of accuracy- guided targeted gene panel, whole-exome sequencing (WES), and whole-genome sequencing (WGS) for DD/ID need prospective analyses of the increasing cost-effectiveness versus conventional genetic testing. Choosing the appropriate sequencing method requires individual planning. Data are required to guide best-practice recommendations for genomic testing, regarding various clinical phenotypes in an etiologic approach. Targeted panel testing may be recommended as a first-tier testing approach for children with DD/ID. Family-based trio testing by WES/WGS can be used as a second test for DD/ ID in undiagnosed children who previously tested negative on a targeted panel. The role of NGS in molecular diagnostics, treatment, prediction of prognosis will continue to increase further in the coming years. Given the rapid pace of changes in the past 10 years, all medical providers should be aware of the changes in the transformative genetics field.


Author(s):  
Е.Г. Окунева ◽  
А.А. Козина ◽  
Н.В. Барышникова ◽  
А.Ю. Красненко ◽  
О.И. Климчук ◽  
...  

Выявление генетической причины наследственного заболевания является необходимым этапом дифференциальной диагностики, играет важную роль при оценке генетического риска, а в ряде случаев также помогает определить метод и тактику лечения. Выбор метода молекулярно-генетического тестирования может представлять большую трудность в связи наличием целого ряда преимуществ и ограничений у каждого из подходов. Методы различаются по диагностической эффективности, времени и стоимости исследования, причем эти показатели могут значительно отличаться при диагностике разных групп генетических заболеваний. Использование неподходящего метода может существенно увеличить время и стоимость диагностики. В последнее время всё больше данных указывает на высокую эффективность одного из подходов секвенирования нового поколения (next generation sequencing, NGS) - экзомного секвенирования для выявления генетической причины некоторых групп наследственных заболеваний. Экзомное секвенирование позволяет получить информацию об изменениях в кодирующих белки областях генов - экзонах. Проведение трио экзомного секвенирования в семьях дополнительно увеличивает эффективность такого анализа. В статье приведено обоснование случаев клинической и финансовой целесообразности назначения экзомного секвенирования. К таким случаям относятся: редкие генетические заболевания, генетически гетерогенные заболевания у детей 0-3 лет, недавно установленная связь гена с заболеванием, тестирование после отрицательного результата других исследований, для пренатальной диагностики, по финансовым причинам. Identification of the genetic cause of a hereditary disease is a necessary step in the differential diagnosis, because plays an important role in evaluation of genetic risk, and in some cases also helps to determine the method of treatment, for example, for some hereditary metabolic diseases. The subsequent choice of molecular genetic testing method can be very difficult due to the presence of a number of advantages and limitations for each of these approaches. Methods of molecular genetic testing in order to identify the genetic causes of a hereditary disease, first of all, differ in diagnostic efficiency, time and cost of the study. In addition, the characteristics of different methods can also vary significantly for different groups of genetic diseases. Using the wrong method can significantly increase the time and cost of diagnosis. Recently, several data indicate that one of the next generation sequencing (NGS) methods - exome sequencing - has high efficacy for identification of the genetic cause of certain groups of hereditary diseases. Exome sequencing provides information about changes in gene coding regions - exons. A trio exome sequencing in families further increases the effectiveness of such analysis. The article describes the examples of clinical and financial feasibility of exome sequencing to identify the genetic cause of a hereditary disease. Such cases include: rare genetic diseases, heterogeneous diseases in children 0-3 years old, recently established connection of a gene with a disease, testing after negative results of other studies, for prenatal diagnosis, for financial reasons.


2019 ◽  
Vol 25 (31) ◽  
pp. 3350-3357 ◽  
Author(s):  
Pooja Tripathi ◽  
Jyotsna Singh ◽  
Jonathan A. Lal ◽  
Vijay Tripathi

Background: With the outbreak of high throughput next-generation sequencing (NGS), the biological research of drug discovery has been directed towards the oncology and infectious disease therapeutic areas, with extensive use in biopharmaceutical development and vaccine production. Method: In this review, an effort was made to address the basic background of NGS technologies, potential applications of NGS in drug designing. Our purpose is also to provide a brief introduction of various Nextgeneration sequencing techniques. Discussions: The high-throughput methods execute Large-scale Unbiased Sequencing (LUS) which comprises of Massively Parallel Sequencing (MPS) or NGS technologies. The Next geneinvolved necessarily executes Largescale Unbiased Sequencing (LUS) which comprises of MPS or NGS technologies. These are related terms that describe a DNA sequencing technology which has revolutionized genomic research. Using NGS, an entire human genome can be sequenced within a single day. Conclusion: Analysis of NGS data unravels important clues in the quest for the treatment of various lifethreatening diseases and other related scientific problems related to human welfare.


Sign in / Sign up

Export Citation Format

Share Document