A decade ago, sequencing the dna in a person’s entire genome cost up to $1 billion, a price so prohibitive that only a few genetics pioneers had the honor of having it done. In 2010 the cost per genome tumbled to less than $10,000, making it possible to study dna variations within a single family. Almost immediately such familial genome sequencing proved its value, uncovering mutations responsible for diseases caused by defects in a single gene. “There are literally hundreds, if not thousands, of diseases falling into this category. This approach will allow us to very quickly find the genetic culprit,” says Leroy Hood, a geneticist at the Institute for Systems Biology in Seattle.
Earlier efforts to hunt down disease-causing genes—so-called genomewide association studies—frequently came up empty-handed because medical researchers had to take cost-saving shortcuts. Instead of trolling an individual’s entire genome, they limited their search to dna regions where ...
