The Human Genome Project

genetic mapping; DNA; applied research; molecular genetics T Human Genome Project is an international research project whose primary mission is to decipher the chemical sequence of the complete human genetic material (i.e., the entire genome), identify all 50,000 to 100,000 genes contained within the genome, and provide research tools to analyze all this genetic information. This ambitious project is based on the fact that the isolation and analysis of the genetic material contained in the DNA1 (figure 1) can provide scientists with powerful new ap­ proaches to understanding the development of diseases and to creating new strategies for their prevention and treatment. Nearly all human medical conditions, except physical injuries, are related to changes (i.e., mutations) in the structure and function of DNA. These disorders include the 4,000 or so heritable “Mendelian” diseases that result from mutations in a single gene; complex and common disorders that arise from heritable alterations in multiple genes; and disorders, such as many cancers, that result from DNA mutations acquired during a person’s lifetime. (For more infor­ mation on the genetics of alcoholism, see the articles by Goate, pp. 217–220, and Grisel and Crabbe, pp. 220–227.) Although scientists have performed many of these tasks and experiments for decades, the Human Genome Project is unique and remarkable for the enormity of its effort. The human genome contains 3 billion DNA building blocks (i.e., nucleotides), enough to fill approximately one thousand 1,000­page telephone books if each nucleotide is represented by one letter. Given the size of the human genome, researchers must develop new methods for DNA analysis that can process large amounts of information quickly, cost­effectively, and accurately. These techniques will charac­ terize DNA for family studies of disease, create genomic maps, determine the nucleotide sequence of genes and other large DNA fragments, identify genes, and enable extensive computer manip­ ulations of genetic data.