tailieunhanh - Ebook Thompson & Thompson genetics in medicine (8th edition): Part 2

(BQ) Part 2 book "Thompson & Thompson genetics in medicine" presents the following contents: Developmental genetics and birth defects, cancer genetics and genomics, risk assessment and genetic counseling, prenatal diagnosis and screening, application of genomics to medicine and personalized health care, ethical and social issues in genetics and genomics. | CHAPTER 12 The Molecular Biochemical and Cellular Basis of Genetic Disease In this chapter we extend our examination of the molecular and biochemical basis of genetic disease beyond the hemoglobinopathies to include other diseases and the abnormalities in gene and protein function that cause them. In Chapter 11 we presented an outline of the general mechanisms by which mutations cause disease see Fig. 11-1 and reviewed the steps at which mutations can disrupt the synthesis or function of a protein see Table 11-2 . Those outlines provide a framework for understanding the pathogenesis of all genetic disease. However mutations in other classes of proteins often disrupt cell and organ function by processes that differ from those illustrated by the hemoglobinopathies and we explore them in this chapter. To illustrate these other types of disease mechanisms we examine here well-known disorders such as phenylketonuria cystic fibrosis familial hypercholesterolemia Duchenne muscular dystrophy and Alzheimer disease. In some instances less common disorders are included because they best demonstrate a specific principle. The importance of selecting representative disorders becomes apparent when one considers that to date mutations in almost 3000 genes have been associated with a clinical phenotype. In the coming decade one anticipates that many more of the approximately 20 000 to 25 000 coding genes in the human genome will be shown to be associated with both monogenic and genetically complex diseases. DISEASES DUE TO MUTATIONS IN DIFFERENT CLASSES OF PROTEINS Proteins carry out an astounding number of different functions some of which are presented in Figure 12-1. Mutations in virtually every functional class of protein can lead to genetic disorders. In this chapter we describe important genetic diseases that affect representative proteins selected from the groups shown in Figure 12-1 many other of the proteins listed as well as the diseases associated with them are described