Drug manufacturers have begun amassing enormous troves of human DNA in hopes of significantly shortening the time it takes to identify new drug candidates, a move some say is transforming the development of medicines.

The efforts will help researchers identify rare genetic mutations by scanning large databases of volunteers who agree to have their DNA sequenced and to provide access to detailed medical records.

It is made possible by the dramatically lower cost of genetic sequencing — it took government-funded scientists $3 billion and 13 years to sequence the first human genome by 2003. As of last year, the cost was closer to $1,500 per genome, down from $20,000 five years ago.