Huntington’s DiseaseHuntington’s disease, also known as Huntington’s chorea is a genetic disorderthat usually shows up in someone in their thirties and forties, destroys themind and body and leads to insanity and death within ten to twenty years.
Thedisease works by degenerating the ganglia (a pair of nerve clusters deep in thebrain that controls movement, thought, perception, and memory) and cortex byusing energy incorrectly. The brain will starve the neurons (brain cells), andsometimes make them work harder than usual, causing extreme mental stress. Theresult is jerky, random, uncontrollable, rapid movement such as grimacing of theface, flailing of arms and legs, and other such movement. This is known aschorea. Huntington’s chorea is hereditary and is caused by a recently discoveredabnormal gene, IT15.
IT stands for “interesting transcript” because of the factthat researchers have no idea what the gene does in the body. Huntington’sdisease is an inherited mutation that produces extra copies of a gene sequence(IT15) on the short arm of chromosome 4. A genetic base that exists intriplicate, CAG for short, is effected by Huntington’s disease. In normal people,the gene has eleven to thirty-four of these, but, in a victim of Huntington’sdisease the gene exists from anywhere between thirty-five to one-hundred or more. The gene for the disease is dominant, giving children of victims of Huntington’sdisease a 50% chance of obtaining the disease.
Several other symptoms of the disease exist other than chorea. High levels oflactic acid have been detected in patients of Huntington’s disease as a bi-product of the brain cells working too hard. Also, up to six times above thenormal level of an important brain brain protein, bFGF (or basic fibroblastgrowth factor) in areas of the brain effected by the chorea. This occurs fromthe problems on chromosome 4, where the gene for control of bFGF is also located. As of yet, there is no treatment for Huntington’s disease. But with thediscovery of the mutated genes that cause it, there is now a way of diagnosingif you will get it.
This technique was discovered only recently and reported inthe Journal of American Medical Association in April, 1993. Something that manypeople do not want to know. Because it can go two ways. Either you are extremelyrelieved because the test shows up negative, and a great burdon is lifted off ofyour mind, or you show up positive, and know how and a little bit about when youwill die, increasing the burdun very greatly.
And living the rest of your lifein depression. Some 30,000 Americans are currently suffering for this genetic disorder. Namedin 1872 for George Huntington the New York Doctor who first wrote down it’sdevestating symtoms, Huntingtons disease up to now was a silent time bomb. 13,000 people, the largest known concentration of sufferers from Huntington’sDisease, live in the Lake Maracaibo region of Venezuela.
The origins of thisgene pool has been traced back to the 1800’s to a woman named Maria Concepcion. It was from blood samples of these people that scientists became extraordinarilylucky and isolated the genetic marker that shows the presence of this disorder. Today, it is believed that Maria obtained the disease when she was birthed by aeuropean sailor. Since it was first recorded by George Huntington, a Long Island doctor,Huntington’s disease had remained fairly low key. No one heard about it until itinfected Woodie Guthrie, A famous folk singer from the 1920’s who showedsymptoms of the disease.
In 1967, he died. This put Huntington’s Disease on themap, but it still was not well known. But, before Woodie guthrie died, he had ason, Arlo Guthrie. He, too became a famous folk singer, this time from theSeventies. He became extremely famous, but had to live with the fact that he hasa 50% chance of having the disorder. That aroused huge public interest and madethe disease well-known.
Now that you know about Huntington’s disease, you can imagine how it works, andthe probability of getting it. But, can you imagine how it feels to have thedisorder? What would it be like to know that you have a 50% chance of notreaching your sixtieth birthday? Now, enter the life of Nancy Wexler, a womanwho knows how it feels for both of these. She watched as her mother died fromthe disease, and has to live with the fact that she may be next. When Wexler wasyoung, three of her uncles died of the killer disease.
“Men only gotHuntington’s disease” went the myth. Then it happened; her sister was told byher doctor that her unusual walk was an early symptom. She too had the disease. Since then, she and her sister Alice, swore never to have children. Years later,Wexler joined up with her husband Milton Wexler, and Marjorie Guthrie, wife ofWoodie Guthrie, and formed the Los Angeles chapter of the Commitee to combatHuntington’s Disease.
Guthrie wanted to focus the organization on patient care,but Wexler was intent on finding a cure. So, she began to invite biologists tohelp study the disease while she worked to get her Ph. D. In 1976 she moved toWashington to become executive director of the Congressional Commission for thecontrol of Huntington’s disease and it’s Consequences. Once there, theydiscovered that Huntington’s disease works by distroying the Ganglia.
Then theydecided that the best way to research Huntington’s disease was at the level ofthe gene. They decided to loook for a “marker” (small identifiable piece of DNA)of where the faulty gene is located. This normally would yave taken 50 to 75years to find. But, on a freak chance, they found it.
it was the 12th markerthat they tested. The discovery of the marker led to the discovery of the genewhich won Wexler the Albert Lasker Public Service Award. The highest honor inAmerican medicine. She also developed a test to accurately determine whether ornot someone will get Huntington’s disease.
Wexler will not reveal if she, herself has taken the test because she does amultitude of genetic counciling, and does not want to sway her patients’decisions on whether or not to take the test. But, whether she tests positive ornegative, Huntington’s disease will live on. Unless scientists like Wexler canfind a cure.
