Part Four - Molecular Biology: The Genome in Action 331

17.  Genome Sequencing, Molecular Biology, and Medicine 374

17.1 How Do Defective Proteins Lead to Diseases? 375 Genetic mutations may make proteins dysfunctional 375 Prion diseases are disorders of protein conformation 378 Most diseases are caused by both genes and environment 379 Human genetic diseases have several patterns of inheritance 379 17.2 What Kinds of DNA Changes Lead to Diseases? 380 One way to identify a gene is to start with its protein 380 Chromosome deletions can lead to gene and then protein isolation 381 Genetic markers can point the way to important genes 381 Disease-causing mutations may involve any number of base pairs 382 Expanding triplet repeats demonstrate the fragility of some human genes 382 DNA changes in males and females can have different consequences 383 17.3 How Does Genetic Screening Detect Diseases? 384 Screening for disease phenotypes can make use of protein expression 384 DNA testing is the most accurate way to detect abnormal genes 384 17.4 What Is Cancer? 386 Cancer cells differ from their normal counterparts 386 Some cancers are caused by viruses 387 Most cancers are caused by genetic mutations 387 Two kinds of genes are changed in many cancers 388 Several events must occur to turn a normal cell into a malignant cell 389 17.5 How Are Genetic Diseases Treated? 391 Genetic diseases can be treated by modifying the phenotype 391 Gene therapy offers the hope of specific treatments 391 17.6 What Have We Learned from the Human Genome Project? 393 There are two approaches to genome sequencing 393 The sequence of the human genome contained many surprises 393 The human genome sequence has many applications 395 The use of genetic information poses ethical questions 395 The proteome is more complex than the genome 395 Systems biology integrates data from genomics and proteomics 396