An urgent need for standards and guidelines on genetic testing has arisen because of swift advances in research, facilitated by the Human Genome Project. The goals of the Human Genome Project include the identification of all genes and sequencing of the human genome. The project is currently ahead of schedule and under budget. We can expect an avalanche of genetic information, much of which will be relevant to human disease. In addition to the Human Genome Project, investigator-initiated research projects and commercial biotechnology laboratories are discovering human disease genes at a breathtaking pace. Technology transfer has been rapid and has led to the availability of numerous clinical tests within only a few years since the first disease gene yielded to the technique of positional cloning. Disease genes are selected for study for a number of reasons. Genes for rare diseases may be studied before more common disorders because they elucidate an important area of pathogenesis. Unfortunately, technology transfer to the clinic for rare tests is hindered by several factors. Standards need to be established to assure that genetic tests for rare diseases are not ignored or mismanaged in the rush to commercialize tests for more common human genetic diseases.