肌营养不良的异常基因突变
Unusual mutation linked to muscular dystrophy
NEW YORK (Reuters Health) - The genetic mutation to blame for the most common form of muscular dystrophy in adults causes disease in a fundamentally different way than most genetic mutations, researchers report.
Typically, a mutation in the genetic material DNA, which encodes instructions for cell growth and development, causes the formation of a defective protein, just as a faulty set of blueprints leads to the construction of an unstable building. But in the case of a form of muscular dystrophy called myotonic dystrophy, the protein produced by a defective gene may not actually cause the disease, according to Dr. Charles A. Thornton, of the University of Rochester in New York.
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This type of muscular dystrophy, which occurs once in every 7,400 births and causes muscle weakness and atrophy as well as cataracts and heart problems, ``seems to have more to do with RNA,'' he told Reuters Health. This cell component is the working molecule that actually translates the genetic instructions of DNA into functioning cell proteins, Thornton explained. It has long been thought to be only a carrier of genetic information, not a ``bad actor'' in disease, he said. Now it appears that the gene mutation--a sort of stutter that leads to a certain sequence repeated over and over--may produce an extra-long RNA sequence that is toxic to muscle cells.
, 百拇医药
Thornton and his colleagues discovered the faulty RNA when trying to develop an animal model of myotonic dystrophy. In the case of most diseases, there is a similar animal version that scientists can use to study the causes of the disease and test therapies, Thornton noted. But until now, there has not been an animal version of myotonic dystrophy, the researcher explained.
``My colleagues and I have been interested in developing treatments for this relatively common disease for a long time,'' Thornton said. ``We couldn't understand what was causing muscles to become weak in the first place. That was the frustration that sparked this research.''
, http://www.100md.com
Thornton's team was able to develop an animal model of the disease, but it worked in a strikingly different way than most. The investigators took the disease-causing mutation and placed it in healthy mice in a gene not linked to the disease. These mice developed symptoms of myotonic dystrophy, even though they were producing extra-long RNA from a gene not normally linked with the disease, the authors report in the September 8th issue of the journal Science.
According to Thornton, “These mice will be useful to...researchers who are interested in finding out why muscles become weak and why the RNA buildup causes muscles to weaken.”
, 百拇医药
The mouse model of the disease will also allow scientists to test drugs to treat the illness, he said.
But much about the causes of myotonic dystrophy remains a mystery, according to Dr. Stephen J. Tapscott, of the Fred Hutchinson Cancer Research Center in Seattle, Washington.
“Another important piece has been added to the myotonic dystrophy puzzle, inevitably drawing our attention to the pieces yet to be placed.” he comments in an accompanying editorial., 百拇医药(Merritt McKinney)
NEW YORK (Reuters Health) - The genetic mutation to blame for the most common form of muscular dystrophy in adults causes disease in a fundamentally different way than most genetic mutations, researchers report.
Typically, a mutation in the genetic material DNA, which encodes instructions for cell growth and development, causes the formation of a defective protein, just as a faulty set of blueprints leads to the construction of an unstable building. But in the case of a form of muscular dystrophy called myotonic dystrophy, the protein produced by a defective gene may not actually cause the disease, according to Dr. Charles A. Thornton, of the University of Rochester in New York.
, http://www.100md.com
This type of muscular dystrophy, which occurs once in every 7,400 births and causes muscle weakness and atrophy as well as cataracts and heart problems, ``seems to have more to do with RNA,'' he told Reuters Health. This cell component is the working molecule that actually translates the genetic instructions of DNA into functioning cell proteins, Thornton explained. It has long been thought to be only a carrier of genetic information, not a ``bad actor'' in disease, he said. Now it appears that the gene mutation--a sort of stutter that leads to a certain sequence repeated over and over--may produce an extra-long RNA sequence that is toxic to muscle cells.
, 百拇医药
Thornton and his colleagues discovered the faulty RNA when trying to develop an animal model of myotonic dystrophy. In the case of most diseases, there is a similar animal version that scientists can use to study the causes of the disease and test therapies, Thornton noted. But until now, there has not been an animal version of myotonic dystrophy, the researcher explained.
``My colleagues and I have been interested in developing treatments for this relatively common disease for a long time,'' Thornton said. ``We couldn't understand what was causing muscles to become weak in the first place. That was the frustration that sparked this research.''
, http://www.100md.com
Thornton's team was able to develop an animal model of the disease, but it worked in a strikingly different way than most. The investigators took the disease-causing mutation and placed it in healthy mice in a gene not linked to the disease. These mice developed symptoms of myotonic dystrophy, even though they were producing extra-long RNA from a gene not normally linked with the disease, the authors report in the September 8th issue of the journal Science.
According to Thornton, “These mice will be useful to...researchers who are interested in finding out why muscles become weak and why the RNA buildup causes muscles to weaken.”
, 百拇医药
The mouse model of the disease will also allow scientists to test drugs to treat the illness, he said.
But much about the causes of myotonic dystrophy remains a mystery, according to Dr. Stephen J. Tapscott, of the Fred Hutchinson Cancer Research Center in Seattle, Washington.
“Another important piece has been added to the myotonic dystrophy puzzle, inevitably drawing our attention to the pieces yet to be placed.” he comments in an accompanying editorial., 百拇医药(Merritt McKinney)