WASHINGTON — An appeals court here has ruled that a company that makes tests for breast and ovarian cancer can patent breast cancer gene sequences, in effect ruling that human genes can be patented.

The U.S. Court of Appeals for the Federal Circuit — a court that specializes in patent cases — ruled that when a gene is isolated from the human body, it is ‘markedly different’ and has a ‘distinctive chemical identify and nature’ compared with the way it is found in nature.

Friday’s 2-1 decision overturns parts of earlier decisions by a U.S. District Court judge in New York City who ruled that patents on the BRCA 1 and 2 gene sequences — and by extension all other human genes — are invalid.

The company that holds the patents, Utah-based Myriad Genetics, sells tests that assess a woman’s risk of developing breast or ovarian cancer based on detection of mutations in the BRCA1 and BRCA2 genes. Other companies, researchers, or doctors that test for the mutation would be violating Myriad’s patent. Companies can still do whole-genome sequencing without violating the patent.

The American Civil Liberties Union (ACLU) and the Public Patent Foundation, along with a group of doctors, genetic scientists, and patients, […]