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DHMC Collecting ALS Data

Lebanon — Three years ago, when Frank Petrosino was diagnosed with a disease that was almost certain to kill him, his family had questions with no certain answers.

“What did we do wrong? How did he get this? How can we prevent it from happening to anyone else, especially our children?” said Heidi Smith, of South Burlington, Petrosino’s wife of 18 years. “Those are all the questions that run through your mind.”

The disease that Petrosino was diagnosed with in 2010 is amyotrophic lateral sclerosis, or ALS, commonly known as Lou Gehrig’s disease. Although it has become widely known for leading to the death of a baseball hero, the factors that cause it remain a mystery.

Researchers at Dartmouth-Hitchcock Medical Center who have been studying ALS are now collecting data in a registry of patients throughout New England to look for possible environmental links to the disease.

In building the registry, physicians hope to learn why cases of ALS have clustered in parts of the Northeast, including around Mascoma Lake in Enfield, said Tracie Caller, a neurophysiology fellow at DHMC who is leading the project.

About 5 to 10 percent of ALS cases are inherited, but the overwhelming majority seem to occur at random with no clear understanding of the risk factors, according to the National Institute of Health.

A national database was started in 2010, but DHMC is working with the University of Vermont to gather specific data from this region. Researchers are working with doctors in New England to enroll patients.

Doctors have been aware of ALS for more than a century and, to date, most of the research has focused on genetics, Caller said. This work on the registry goes further to look at the role environment plays.

“We’ve looked really at genetics and we still can’t account for the causes in 90 percent of people,” she said. “We want more detailed data for us to review and do our own (registry) regionally, simply because there’s some environmental exposures we’re interested in studying up here.”

ALS is a progressive, usually fatal neurodegenerative disease that causes nerve cells to stop functioning and eventually die, according to the U.S. Department of Health and Human Services. It can cause muscle weakness, paralysis and eventually death. No one knows how many people are living with ALS, but it is estimated that about 30,000 people in the U.S. have the disease. In Vermont, 20-30 people die annually from ALS and, in New Hampshire, ALS accounts for more than 40 deaths every year, Caller said.

So little is known about ALS in part because patients do not live very long after diagnosis, typically only a couple of years, said Rup Tandan, professor and vice chairman of neurology at UVM, who is working with Caller on the registry. That makes finding enough patients to study difficult.

“It’s a devastating disease and it really knocks people off their boots when they get the disease,” Tandan said.

Creating a database of patients that includes demographic information, residency history, past exposure to various toxins and, eventually, DNA samples will help researchers study patterns and potentially identify causes of ALS.

In 2009, Caller and her colleagues noted a possible link between certain algae blooms that produce a neurotoxin that may trigger the disease. Nine people living near Mascoma Lake have been diagnosed with ALS since 1990, all but one between 2000 and 2007, putting the prevalence there about 25 times greater than national norms, Caller said. Dartmouth researchers were trying to figure out whether the Mascoma Lake cases were related to outbreaks of cyanobacteria in the water. Sometimes called “blue-green algae,” cyanobacteria are photosynthetic, single-celled organisms that are common in lakes and ponds around the Twin States. The suspected ALS trigger is a neurotoxin that can be produced by cyanobacteria and has been found in brain samples of ALS patients.

Researchers continue to investigate other possible causes, Caller said, including pesticides and methylmercury, a toxin that has been found in some fish.

So far, they’ve found nothing definitive that links the ALS to any single environmental factor.

“The major limitation now is getting funding to do sufficient sampling to really look for how people might be exposed,” she said. “Our initial thought was it seems like people who live around the (Mascoma) Lake are developing ALS at a higher rate, but we don’t know why. Somehow, it may not just be living near it, but it may be fish consumption or water consumption if they’re drinking untreated water.”

Researchers are looking at Lake Champlain as well, Tandan said. But not every cluster has been near a large body of water. A handful of cases have been found in Plainfield, Vt., a farming community about 10 miles east of Montpelier along Route 2.

“We’re interested in agriculture,” Caller said. “There have been some reports of pesticides being linked to ALS. Nothing has been conclusive thus far but that’s something that people get exposed to in our region that we’d like to investigate a little bit further.”

Researchers suspect that there is more involved than exposure to toxins, she said. More likely is that people who develop ALS have some kind of genetic susceptibility to the disease combined with environmental factors, similar to some cancers. Just because a person is exposed to arsenic or asbestos doesn’t automatically mean that person develops lung cancer, she said.

The data collected through the regional registry will help doctors investigate these questions. Currently, patients cannot enroll in the New England registry themselves and must be enrolled through their doctors. Caller said it would be important for patients to sign up for the national registry, too, which they can do themselves online.

Pat Wildman, of the Washington, D.C.-based ALS Association, agreed that registering for both is important. His organization played a key role in getting congressional approval for the national registry and wants it to be a central repository for ALS research. His concern with regional efforts like the one in New England is that patients would be confused or feel overly burdened. New Hampshire is among the states that has had lower-than-expected participation in the national registry, he said.

Still, Wildman said, he supported Dartmouth-Hitchcock’s efforts.

“Really, anything we can do to advance the cause is a good thing,” he said. “We just hope people also participate in the national registry.”

Smith, in South Burlington, said her husband is part of the national registry and they plan to participate in the New England one, as well. They want to do anything they can to help fight the disease.

“This isn’t a new illness. It’s been around since the late 1800s and we need to find a cure,” she said. “We need to find a cause and a cure. It’s just crazy that there’s no known cause yet and I think the registry is one key aspect to doing that.”

Chris Fleisher can be reached at 603-727-3229 or cfleisher@vnews.com.