The controversial 1998 patent that gave Myriad Genetics a US monopoly over genetic testing for risk of breast and ovarian cancer contains a claim so “surprisingly broad” that it should never have been granted, says an article in the journal Genomics.

Three researchers from the Institute for Genome Sciences and Policy at Duke University, North Carolina, found that stretches of DNA claimed in the BRCA1 patent are common throughout the human genome and could be found in 80% of the gene sequences placed in the publicly accessible GenBank, the genetic sequence database of the National Institutes …