NEW YORK A huge catalog of human DNA is helping researchers find tiny glitches that cause disease, in part by pointing out some false leads.
The database, with genetic codes from more than 60,000 people, is aimed at researching rare diseases that are generally caused by a single malfunctioning gene. Most of these diseases are so uncommon that the general public has never heard of them, but there are thousands of such conditions, and as a group they affect about 1 percent of births.
Better accuracy in identifying the genetic cause of a person’s disease provides a “clear and direct benefit to patients,” said Daniel MacArthur of the Broad Institute in Cambridge, Massachusetts, and Massachusetts General Hospital in Boston.
He is senior author of an analysis published in the journal Nature by researchers who compiled the database, which draws on DNA data from more than two dozen disease studies. It went online in 2014 and has since been consulted more than 5 million times, he said.
For rare diseases, doctors try to find the genetic cause by analyzing the patient’s DNA. But everybody carries tens of thousands of minute differences from the standard DNA code, and the goal is to find which one or two of them is making the person sick.
Researchers frequently do that through guilt by association. If a variation shows up in a patient, but it is never seen or extremely rare in others, it may be fingered as the cause of disease.
