It seems obvious that a company shouldn’t hold a patent on something that the human body produces. Proprietary patents, after all, protect the exclusive rights to make, use or sell a creation or invention — not something that occurs in nature.

Yet some 30 years ago, the U.S. government started issuing human gene patents to companies that do biomedical research. But last week, the U.S. Supreme Court ruled unanimously on what should have been apparent all these years. Justices rightly said that human genes cannot be “owned’’ or patented.

That’s a victory for health care consumers. They will have more access to genetic and other tests at lower cost. And it’s good for medical research, because scientists can conduct studies on genes without fear of being sued.

At the same time, the court ruled that companies can continue to patent a type of synthetic DNA that goes beyond simply isolating genes. The distinction can help companies protect their research and development investments.

The case involved a suit against Utah-based Myriad Genetics Inc., which was first to isolate the genes that have been linked to breast and ovarian cancer. Because of the patents Myriad held on the BRCA1 and BRCA2 genes, it was the only company that could offer tests for them. American Civil Liberties Union lawyers brought the suit challenging that monopoly on behalf of doctors, researchers and cancer patients.

Fortunately for patients, the high court said that gene patents of this kind are not valid. In the court’s unanimous decision, Justice Clarence Thomas wrote: “Myriad did not create anything. … To be sure, it found an important and useful gene, but separating that gene from its surrounding genetic material is not an act of invention.’’

Last month, BRCA1 and 2 testing received national attention when actress Angelina Jolie revealed that she had a preventive double mastectomy after testing positive for the gene. But because they hold gene patents, biotech firms like Myriad have had monopolies on some genetic tests and have controlled the prices for those tests. Breast and ovarian cancer screening can cost more than $3,000, and some insurers won’t cover it for women with an average risk for the gene mutation. But now that the gene patent is invalid, other companies can offer the tests — often at much lower cost.

Though it was done for decades, it was never right for a company to have a monopoly over something created naturally by the human body. The court made a wise decision on behalf of millions who will benefit from more affordable, accessible medical tests and individually targeted treatments.