Saturday, December 02, 2006
Breakthrough in cause of ALS
It appears a major breakthrough has been made in the cause of ALS. Below is a release about the announcement that was made at the International MND Symposium yesterday.
I'm glad Hing and I were participates in the DNA study. It gives me hope.
Researchers at the Translational Genomics Research Institute say they believe they have determined the genetic causes of Lou Gehrig's disease, offering hope that effective treatments for the dreaded ailment may finally be available in a few years. Researchers at the Phoenixbased institute said they have identified more than 50 genetic abnormalities in people with sporadic amyotrophic lateral sclerosis, or ALS. The finding, made public today, may make it easier to identify drugs that could halt or reverse the negative effects of those flaws.
The most common of the gene defects have never before been shown to play a role in the neuromuscular disease, the institute said.
The findings were announced earlier today at an international ALS conference in Japan.
"We have identified a fundamental understanding of what causes the disease," said Dietrich Stephan, director of neurogenomics for the institute. "With that information, we can now move forward with a knowledge-based drug exercise." He said the institute has started testing compounds that might counter the impact of the gene flaws on the nervous system. "What we are shooting for is to reverse the course of the disease," he said.
"We would be happy to just stop the progression of the disease, but we want a compound to reverse it. We have evidence that it is possible." He said the time needed to develop those drugs could be from months to as long as 10 years, but he said two years is a likelier time frame. If existing medicines can be found that have an impact on the disease, approval by the U.S. Food and Drug Administration would happen faster than if new compounds must be developed, he said.
An existing drug called Rilutek has been found that slows the progression of the disease.
The $652,000 research project, which was funded by the Muscular Dystrophy Association, involved the screening of DNA samples from more than 1,200 people with sporadic ALS, the most common form of the disease, and 2,000 people without the disease. The researchers used state-of-the-art microchips developed by the Affymetrix Co. of Santa Clara, Calif. to compare the genetic makeup of ALS patients with that of nonaffected individuals.
The identified differences implicate genes that probably play a role in controlling the adhesion of nerves to the muscles, which opens a new avenue for ALS research, Stephan said. "Our findings indicate these genes produce a sort of molecular glue that attaches motor neurons to muscle. It appears that in ALS the nerve is able to peel off the muscle and, when that happens repeatedly, the nerves die," he said.
Because the brain can no longer initiate and control muscle movements, the muscles in an ALS patient weaken and deteriorate. As a result, ALS patients develop problems with dexterity, speaking and swallowing. Eventually, the patient becomes paralyzed, and in three to five years death will result when the lungs cease to function. Through it all, however, the victim is conscious and can feel pain.
There are no effective treatments, although the disease has been known for nearly 140 years. Lou Gehrig, New York Yankees star of the 1920s and '30s, was its most famous victim, and his name has been associated with it ever since.
"It's a horrible disease," Stephan said. "The neurologists who deal with the disease have it really rough. There is not too much they can offer these folks."
About 30,000 people have ALS in the United States at any one time. About 95 percent of cases are sporadic ALS, which occurs randomly, or sporadically, within the population. About 5 percent suffer from hereditary ALS, which runs in families and is better understood.
The MDA is "very enthusiastic" about the research by the Phoenix institute, said Ron Schenkenberger, senior vice president of the association.
"The sporadic form has baffled scientists for decades," he said. "Many drugs have been tested and avenues of research pursued. ... What we sought out was to determine if there are any common factors in people with sporadic ALS. That is the whole point of this science."
The project was possible because new semiconductor developments enable researchers to scan human genes more quickly, scientists said. The Affymetrix 500K microarrays used by the institute employ similar technology used in super computers, allowing the ALS study to be completed in nine months.
"Just a couple of years ago, this experiment would not have been possible because there simply wasn't a technology that enabled scientists to sift through the 3 billion molecules in the genome to find the genetic abnormalities that cause disease," said Sean George, vice president of Affymetrix.
"There is a revolution going on in research, and this study is a perfect example of how things are changing," said Sharon Hesterlee, MDA vice president of translational research. "New technology is letting us look at the genome at a level of detail that was unthinkable just a few years ago." Affymetrix scientists invented the first high-density microarray in 1989 and began selling them commercially in 1994. The gene chips, which are about 1 centimeter square, had to be further reduced in size before the complex ALS study could be accomplished, Stephan said.
The same technology is being used in searches for gene abnormalities that might cause other diseases such as diabetes, he said.