The index's 13 percent gain was below the 39 percent surge of 2017 but occurred despite the poor performance of index stocks in December.
The firm said clinical services revenues fell during the quarter due to reduced insurance reimbursement payments and mix of testing in the prior year.
After six straight months of gains, the index saw a sharp drop in October that even positive earnings news could not stave off.
The firm said the decline in Q4 revenues was due to an account loss as well as lower insurance reimbursement and shifts away from high-value genetic testing.
Natera led the Index for the second month in a row after it announced that it intended to raise $75 million in a public stock offering.
Natera led the Index with a 61 percent increase in stock price, driven by the firm's announcement that it was entering the transplantation market.
The firm said that the decline was due to a customer shifting to internalizing genetic ordering, adverse weather, and the loss of an undisclosed commercial payor.
The decline matched the struggles of the broader stock market, though bright spots could be found with GenMark, Quidel, and NanoString all having good months.
The firm said the increase in overall revenues was due largely to a 4 percent increase in clinical labs revenues, while product revenues inched up 1 percent year over year.
Thermo Fisher Scientific says it will no longer sell machines in China's Xinjiang region, according to the Wall Street Journal.
New Scientist reports that 20 percent of human and yeast proteins are uncharacterized.
The University of Zurich's Ruedi Aebersold and his colleagues analyzed a dozen HeLa cell lines to find differences in gene expression, protein levels, and more.
In Nature this week: protein-coding variants associated with body-fat distribution, and more.