A metaphorical pipeline that represents throughput of various processes involved in identifying the causative gene variation for a heritable disorder and its evolution. (a) In the 1980 s and 1990 s, the throughput of genotyping and linkage mapping, physical mapping of genes, and sequencing of candidate genes were limiting factors in this overall process. (b) In the late 1990 s and into the first decade of the 21st century, the limitations of physical mapping were overcome by the Human Genome Project. (c) More recently, very high throughput chip-based SNP genotyping and next-generation sequencing technologies have eliminated the linkage and sequencing bottlenecks. Thus, the clinical analyses at the front and back ends of the process are now limiting and efforts to improve our ability to generate, archive, and analyze these data are necessary. Modified from with permission from .