The suit alleges that Natera's Panorama test infringes US Patent No. 9,493,831 patent, which covers sequencing library preparation methods applied to maternal blood samples.
In Q4 Natera tallied revenues of $53.8 million compared to $49.3 million a year ago, falling short of the consensus Wall Street estimate of $57.1 million.
Natera and Qiagen have signed a 10-year agreement to develop cell-free DNA assays for use on Qiagen's GeneReader next-generation sequencing system.
The company agreed to settle a lawsuit alleging it improperly billed government health plans for its genetic tests.
The 360Dx Index was down 3 percent in February, reflecting similar losses in the broader markets. GenMark Diagnostics and Opko Health were the biggest decliners.
Leading the gainers in the 360 Index was GenMark, whose stock price was up 30 percent last month. Invitae led the decliners as its share price fell 24 percent.
Luminex was bullish about its molecular diagnostics business, Natera outlined its work with pharmaceutical firms, and Oxford discussed its plans in TB and tick-borne diseases.
Natera said its liquid biopsy assay Signatera is well suited for the immuno-oncology field, particularly pharmaceutical companies developing personalized vaccines.
The molecular diagnostics company reported total revenues of $56.7 million in the quarter, and saw its testing volume grow 15 percent over Q3 2016.
Researchers at Aarhus will use Natera's liquid biopsy assay to monitor colorectal cancer patients after surgery and chemotherapy.