Scientists and physicians are organized to start multicenter clinical trials the moment a suitable investigational treatment for Huntington's disease is available.
But while they're ready to go and there are several promising potential treatments being studied, it could be years.That's the word from Dr. Anna B. Young, researcher and clinician at Harvard Medical School in Boston. She presented the Jerome Joseph Landa Memorial Lecture in neurology Monday at the University of Utah Health Sciences Center.
Such a clinical trial will have added importance because scientists believe that treatment for a degenerative neurological disease like Huntington's disease will also impact other neurodegenerative disorders, including Alzheimer's and Parkinson's disease.
"As we find answers for one of them, it is likely we'll start to understand all of them," Young said.
Huntington's disease is both rare and devastating, affecting about 10 of 100,000 people. In the United States, as many as 40,000 have the disease and more than 150,000 are "at risk." The disease is passed down through a direct line from an afflicted parent to children, each of whom has a 50 percent chance of inheriting it. Though the average age of onset is about 35, a 2-year-old has been diagnosed, as has an 80-year-old. And the disease, which has "a long, miserable course" of about 16 years, results in personality changes, movement disorders, dementia and more.
Scientists are just beginning to unravel what causes the genetic defect. They know an expanded sequence of code in the DNA in a certain spot results in the disease, but they don't know why. "And we don't know how the proteins normally function."
Cell death starts in the brain's caudate nucleus. The HD gene causes a protein, huntingtin, to be produced. That protein shrinks as cells age, cut up by members of the caspace chemical family. As the protein gets smaller, the pieces become more toxic and the smaller bits migrate into the cell's nucleus.
But researchers have some hope, based on research using mice that have been genetically altered to have a Huntington's disease-like condition. They have found that inhibiting the caspace seems to delay the onset of the disease.
Researchers have also found that giving mice with the disease tetracycline seems to "turn the expression of Huntington's disease off. The animals recover some. They are not back to the baseline, but they do get better -- somewhat."
Young believes the research indicates there are stages of the illness where the cells are sick but can recover to some extent. If the offending proteins were eliminated, the cells might be able to rejuvenate.
If it proves out, it could be significant for Parkinson's and Alzheimer's, too, she said.
The work is being done in mice; researchers are anxious to see if it works for humans. But clinical trials could be a long time coming.
Young believes eventually the focus will shift from treating those who are sick to treating those who are at risk for the disease. One day, perhaps, she said, "we could intervene and turn the (defective) gene off."
That's all in the future somewhere. Currently, there are no effective interventions. And treatment has a long, long way to go, she said.
You can reach Lois M. Collins by e-mail at lois@desnews.com