Some genetic mutations that have been thought to be harmful are turning out to be innocuous, Nature News reports.
It traces many of these reversals to the development of the Exome Aggregation Consortium (ExAC) by Daniel MacArthur at Massachusetts General Hospital and the Broad Institute in 2012. MacArthur had been studying rare muscle diseases, searching for mutations that might be behind them, but he didn't have enough exome sequences from unaffected people, so he cajoled colleagues to share their datasets with him. This year, MacArthur and his colleagues reported in a Nature paper that through ExAC, they identified 3,200 genes likely involved in human genetic disorders. They also found, though, nearly 200 variants that had been thought to be pathogenic that are not, Nature News notes.
This dataset has also helped researchers like Sonia Vallabh and Eric Minikel who are studying whether a mutation in PRNP that Vallabh has is linked to the prion disease that killed her mother. Using ExAC, they could better gauge if that variant, D178N, has been seen in a healthy population and how rare it is. While they found 52 people in ExAC with PRNP mutations that had been linked to prion disease D178N was not one of them, and it still is likely to cause disease, Nature News says.