LabCorp (NYSE:LH), which just this week launched its genetic tests for breast cancer, is now being sued by Myriad Genetics (NASDAQ:MYGN) for patent infringement.

Burlington-based LabCorp on Monday announced the nationwide availability of its BRCAssure tests, a suite of tests to identify patients who have the BRCA gene mutations that indicate an increased risk for breast, ovarian and other cancers.

A day later, Salt Lake City-based Myriad filed suit in in the U.S. District Court for the District of Utah, Central Division, Genome Web reported. Myriad is asking the court to rule that LabCorp has infringed on its patents, that LabCorp be blocked from selling its BRCAssure tests and that the company pay unspecificed damages.

Myriad is the the company that earlier this year went all the way to the U.S. Supreme Court with a case seeking to patent human genes. Myriad had developed tests for the mutations on the BRCA-1 and BRCA-2 breast cancer genes. In the spring, the high court ruled that human genes can’t be patented. That decision ended Myriad’s monopoly on the BRCA gene and opened the door for LabCorp and others to introduce their own tests for the BRCA gene mutation.

But Myriad still claimed victory from the Supreme Court decision because that ruling allowed patents on synthetic DNA, or cDNA. That means that Myriad can still claim patent protection for the parts of its technology that are based on articifical genes that are created in a laboratory.

Another genetic testing company, 23andMe, has been in the headlines lately for selling and marketing its tests without getting the proper authorizations from the Food and Drug Administration. In a response to a query from WRALTechWire, F. Samuel Eberts III, LabCorp’s chief legal officer and senior vice president of corporate affairs, drew the distinction that unlike 23andMe LabCorp is not selling a direct to consumer test. LabCorp’s test is offered to physicians to order for their patients if clinically appropriate.

While it’s clear that LabCorp’s tests are different than 23andMe’s offering, it must now draw a distinction between its test and those of Myriad Genetics. That distinction could now hinge on a legal interpretartion of whether the LabCorp offering is based on the BRCA gene or a synthetic gene that Myriad has patented.