Genomics in the Courtroom-A Revolution in Causation?


The year is 2026. A manufacturer is accused of sickening someone with a toxic product. The defense files a by-now-routine demand for a chip containing the plaintiff’s genome—his entire genetic information—looking for evidence that its product wasn’t the root cause of the illness.

That day is coming, according to Professor Gary Marchant at Arizona State University Sandra Day O’Connor College of Law, Tempe, Ariz.

“It will become routine in ten years to look at the plaintiff’s genome on a chip. And the attorneys on both sides should be cross-examining that information,” he said.

Genetic information could show that the plaintiff was predisposed to a disease, that he was exposed to a toxin, or that he suffered genetic damage.

And some genomic evidence is already being used to establish causation in toxic tort cases.

Traditional causation in toxic tort cases involves epidemiological evidence, which attempts establish to whether there is a correlation between a risk factor and the incidence of the disease in the group exposed to the risk.

Genomics, on the other hand, involves an examination of the genome and its interaction with environmental factors.

Legal experts agree that genomics will be increasingly important in toxic tort cases. But whether it will replace epidemiology is disputed.

“We’re moving away from epidemiology, which looks at groups of people and is a very crude tool for causation in an individual,” Marchant said. “But there may still be a use for epidemiology in general causation.”

Marchant’s research interests include the use of genomics, legal aspects of personalized medicine, and regulation of emerging technologies.

‘Black Box’ Evidence

“Until the genomic revolution, we used `black box’ analysis,” said Dr. David Schwartz of the scientific consulting firm Innovative Science Solutions LLC.

In that model, causation is established by looking at exposure and outcome.

“Now with genomics, we can say, for example, that this particular disease wasn’t caused by this toxic substance,” he said.

“The science is well beyond where it’s being used in the courtroom,” Schwartz said.

“It will become common, but it’s hard to say when that will happen.”

Professor Steve Gold at Rutgers School of Law, Newark, N.J., agrees genomics will make a difference, but urges caution.

Gold has written extensively on genomics and causation in toxic torts.

“The early writing is breathless, but I don’t think it will provide the answer,” he said.

“Genomics will be very important, but I don’t think it will replace epidemiology,” he said.

Even in a world of genomics, Gold says, courts will still be dealing with probability.

General, Specific Causation

To date, epidemiology has been used to establish general causation—for example, that a defendant’s cigarette can cause lung cancer, Gold said.

“You compare groups of people who smoke with those who don’t and that will give us a pretty strong clue.”

“But now that we know we have someone who smokes and gets lung cancer, how do we know that this defendant’s cigarette caused this person’s cancer? That’s specific causation.”

“When we think of a new technology, we ask how it can help with general and specific causation.”

Epidemiology, animal exposure and molecular work have historically been used to show general causation, Gold said.

“The ability to add a genetic layer may allow you to find relationships. That’s an area that’s advanced.”

“But proponents of genomics say we will be able to answer specific causation with certainty,” he said.

“Take for example a tanker truck driver, who inhales benzene in the course of his job and develops leukemia. These are tough cases.”

“Will it be possible to look at cancer cells and say `benzene-induced cancer looks one way and this looks another?’ That is the dream about which I am most skeptical,” Gold said.

Even with genomic evidence, most of the time we won’t be able to say “this toxin caused this person’s cancer,” Gold said.

“Even if we can say that this person was exposed to this chemical, does the marker tell me how much he was exposed? Does it tell me if it caused the disease?”

“If someone gets mesothelioma, by and large, people accept it was caused by asbestos,” he said.

But with lung cancer, for example, smoking is not the only cause. “You may have bad genes or radon exposure. It’s not a signature disease.”

“Is it possible that there will be a disease/exposure relationship that will show only characteristics of this disease? It likely will happen. But I haven’t seen anything showing that will be a pattern,” Gold said.

Genetic Blueprint

In 2003, scientists mapped the human genome, allowing us “to read nature’s complete genetic blueprint for building a human being,” according to the National Institutes of Health.

The Human Genome Project built on the work of scientists that stretched more than 140 years, and which continues to this day.

“It started before the Human Genome Project,” Marchant said. Going back to Ancient Greece, he said, it was known that some people are more susceptible to disease than others.

Toxicogenomics looks at the interaction between genetic material and a toxin.

To determine causation, scientists can look at genetic biomarkers—DNA or RNA tests that show susceptibility to disease or exposure to a toxin.

In addition, Marchant says, scientists can look at biomarkers of effect—for example, whether there is a chromosome break.

Tip of the Iceberg

“Lawyers have been slow to pick up on this,” Marchant says. “There’s been a trickling of cases, but it’s starting to pick up. But most of these are at the trial court level and often result in settlement.”

In 2011, the First Circuit ruled that a plaintiffs’ expert should have been allowed to testify regarding biomarkers, in Milward v. Acuity Specialty Products Group Inc., 639 F.3d 11, 2011 BL 74218 (1st Cir. 2011).

In that case, the plaintiff alleged that benzene caused his rare form of leukemia. The trial court found that benzene hadn’t been linked to the “characteristic genetic alteration.”

Reversing, the First Circuit said the expert witness inferred causation “from the accumulation of multiple scientifically acceptable inferences from different bodies of evidence.” That is, the scientific foundation for the genomic evidence was deemed sound.

A more recent case ended in settlement and involved bladder cancer allegations over the diabetes drug Actos (30 TXLR 430, 4/30/15).

In 2014, the federal trial court overseeing the Actos litigation ruled that a plaintiff’s expert could present genomic testimony, in In re Actos (Pioglitazone) Prods. Liab. Litig., 2014 BL 178118, No. 12-cv-00064 (W.D. La. 2014)).

While there are few reported cases, Marchant says, plaintiffs have already used genomics to show that a mutation is unique to the type of exposure, and defendants have argued that the cancer at issue was caused by natural mutations.

“We don’t need 100 percent certainty,” Marchant said.

“We’ve never had specific causation before. This is revolutionary and it enhances justice,” he said.

Talc, Asbestos ..

While courtroom genomics is still in its infancy, sources agree it will play an increasingly common role.

“It will be used in a wide range of cases,” Marchant said. “Any chemical exposure will lead the way.”

Schwartz suggests that the science will be more useful in some cases than others.

“On one extreme, if there is a well-defined mesothelioma in a 60-year-old man who was exposed to asbestos, that’s a clear causation case where genomics won’t do you any good. But with, for example, a young woman with no history of exposure—that’s a case where genomic evidence is ripe to bring in.”

The science will be especially useful in asbestos—the longest running mass tort—and in the newly emerging area of talc litigation, defense attorney Kirk Hartley with LSP Group LLC, Chicago, told Bloomberg BNA.

Talc came to the attention of many people in February 2016, when a jury awarded $72 million to the family of a woman who died of ovarian cancer allegedly caused by Johnson & Johnson’s talcum powder.

In May, another jury awarded $55 million to a 62-year-old woman in a different talc suit against J&J (31 TXLR 424, 5/5/16).

Hartley’s practice includes asbestos defense. He is also director of a national consultancy, Gnarus Advisors LLC in Arlington, Va., which includes work on the intersection between science and tort law.

“If a person with cancer is being treated at a world-class hospital, their tumor probably has been sequenced as part of their treatment workup. At the other end, multi-gene tests are now being run for less than $5,000,” Hartley said.

“Today we can clearly sequence DNA. What is less clear is how a mutation interacts with exposure. A lot of work is being done on this,” he said.

Article Credit: BNA