Myriad Genetics Inc. (NASDAQ:MYGN) was fending off competition unleashed by the loss of its BRCA patents, only to see a CMS reimbursement decision send the company's shares plummeting to their lowest point since January 2012.

Last Monday, Myriad fell $3.35 (14%) to $20.79 after CMS confirmed it will nearly halve the reimbursement rate for tests that detect mutations in the breast cancer 1 early onset (BRCA1) and BRCA2 genes.