Diagnostic Genetic Testing - Bourn, David

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Résumé :
Over the last decade, technical advances have allowed genomic testing which provides a great opportunity for diagnosis but also an increased chance of uncertain or unexpected findings. This book addresses many of the questions that arise in this context and summarizes the essential concepts in diagnostic genetic testing in an easy-to-read manner. It also covers some broad context for the practical and ethical implications of examining human DNA sequences. The book starts with a general introduction to the field, providing enough background to allow readers without any previous education in genetics to comprehend the material in the subsequent chapters. The main part explores differing aspects of human genetics and the wider implications of testing in these areas. The author covers not only single gene inheritance, but also genetic testing of cancers and how testing benefits the patients. Special emphasis is also given to the questions of genetics and identity. The concluding part then draws the main themes together and summarises the wider significance of genetics. It also explores the gap between promises made for the impact of advances in genetics, and the actual benefits to patients. The book is written for everyone interested to learn about the process of genetic testing and the broader implications. Moreover, it is aimed at health professionals with an interest in genetics, at students or scientific trainees looking for an introduction to diagnostic genetics, and at professionals in health policy or health journalism.

Biographie:
David Bourn, Ph.D., FRCPath, is a UK-based state registered clinical scientist and the head of an NHS Regional Genetics laboratory, who has worked in the NHS for more than 25 years. Prior to his involvement in diagnostic genetics, he spent some years in research, with his Ph.D. and the bulk of his postdoctoral work in the field of human molecular genetics. His links with Human Genetics Departments go back to the 1980s and in addition to his familiarity with the evolution of genetic testing over the past three decades, he has an enduring interest in the wider implications of this testing....

Sommaire:
Chapter 1: Genetic testing, some themes and some basics

? Brief introduction to genetic testing.

o Complexity

o Risk and uncertainty

o DNA and identities

o Future promises and limitations

? Genetic basics

o Information storage and copying

o Genes in genomes (nuclear and mitochondrial)

o Transcription, translation and the genetic code

o Mutation

? Basic techniques of genetic testing

o DNA extraction

o Hybridisation

o Electrophoresis

o DNA sequencing

Chapter 2: Huntington disease, a severe autosomal recessive disorder

? Huntington disease (HD)

? Mutation mechanism and gain of function

? Trinucleotide repeat expansions

? Penetrance and genotype/phenotype correlation

? Anticipation

? Testing for HD and test metrics

? Laboratory error

? Ethical problems (sharing information)

Chapter 3: Autosomal recessive inheritance and cystic fibrosis

? Cystic fibrosis (CF)

? Spectrum of mutations

? Recessive disorders in populations (founder effect)

? Rationales for testing including neonatal screening

? Prenatal diagnosis and ethical issues

? Genetics and therapy for CF

? Risk and uncertainty

Chapter 4: X-linked inheritance: a question of gender

? Chromosome number / balance (XX vs. XY) and X-inactivation

? DNA methylation and epigenetics

? DMD/BMD (genotype/phenotype correlation)

? Sharing genetic information

? Androgen receptor gene and different phenotypes

? Genetics and gender

Chapter 5: Cancer genetics: acquired and inherited mutations

? Cancer as a genetic disease

? Tumour suppressors and oncogenes in the control of growth

? Somatic/germline distinction

? Genetic stratification and cancer treatment

? Future possibilities: liquid biopsy / ctDNA

Chapter 6: Genes and identity

? Forensic and laboratory identity testing

? Uses of short tandem repeat markers in diagnostic genetics

? DNA as a measure of identity

? Relationships within and outside humanity

? Problems with the concept of personal identity

Chapter 7: Genome scale testing

? Development of methods from chromosome analysis to next generation sequencing

? Testing strategies (whole genome, whole exome, gene panels)

? Assigning pathogenicity

? Polygenic / multifactorial inheritance

? Limitations and the ethics of inflated claims

Chapter 8: DNA testing- pulling the strands together

? Fundamentals of genetic testing and access to testing

? Consent

? Avoiding harm

? Uncertainty, risk and biases

? Benefits of genetics

? The language of genetics (in the genetic code and in everyday language)

Appendix: List of technical terms with page references to a definition in the text