ABSTRACT
The recent completion of a high-quality, comprehensive sequence of the human genome has fostered the search for the genetic component of most human diseases. Since Avery, McCloud, and McCarty demonstrated 60 years ago that DNA is the genetic material1 and the double-helical antiparallel, complementary nature of DNA was discovered by James Watson and Francis Crick several years later,2 genetics has become an integral part of our lives. Interwoven advances in genetics, comparative genomics, high-throughput biochemistry, and bioinformatics are providing biologists with a markedly improved repertoire of research tools that will allow the functioning of organisms in health and disease to be analyzed and comprehended at an unprecedented level of molecular detail.3 As of 12 February 2004, 11 283 Mendelian conditions have been mapped to a particular chromosomal location (OMIM, 2004), and nearly 1500 genes associated with disease have been identified. GeneTests (https://www.genetests.org/) lists more than 1030 diseases for which there are molecular tests, 690 of which are clinically available.
