Jef Akst in The Scientist:
When Wellcome Sanger Institute geneticist Eugene Gardner set out to look for a specific type of genetic mutation in a massive database of human DNA, he figured it’d be a long shot. Transposons—also known as jumping genes because they can move around the genome—create a new mutation in one of every 15 to 40 human births, but that’s across the entire 3 billion base pairs of nuclear DNA that each cell carries. The sequencing data that Gardner was working with covered less than two percent of that, with only the protein-coding regions, or exons, included. Doing a quick calculation, he determined that, in the best-case scenario, he could expect to find up to 10 transposon-generated variants linked to a developmental disease. And “we really might get zero,” he says. “This whole thing might be for naught.”
But Gardner had recently developed the perfect tool to find the sort of de novo mobile element insertions that come about as a result of transposon movements and are often overlooked in genetic screens and analyses. As a graduate student in Scott Devine’s lab at the University of Maryland, Baltimore’s Institute for Genome Sciences, he had spent many hours making the software for the mobile element locator tool he dubbed MELT. The program was easy to use, so when Gardner moved across the Atlantic for a postdoc in Matthew Hurles’s lab at Sanger near Cambridge and gained access to a database of exomes from 13,000 patients with developmental disorders, he figured running the tool was worth a try.