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.
The Index underperformed the Dow, Nasdaq, and Nasdaq Biotechnology Index, reversing gains it had made in October and November.
A genome-wide association study highlights a potential role for hair follicles in acne risk, according to New Scientist.
Newsday reports that breast cancer genetic testing guidelines for are out of date and may miss individuals.
In Cell this week: gene editing-based strategy to screen for immune system regulators, ancient plague patterns, and more.
Publication of He Jiankui's work on gene-edited infants would raise ethical concerns for journals, Wired and others report.