Scientists are gaining greater understanding of the genetics behind multiple sclerosis -- an autoimmune disease that affects the central nervous system -- with the discovery of 48 genetic variants that are linked with the condition.
The discovery of these genetic variants, which is detailed in a study in the journal Nature Genetics, brings the total number of known genetic risk factors for the disease to a total of 110.
Individually, each genetic variant is only responsible for a very small risk for multiple sclerosis. But when taken together, the 110 genetic variants "explain approximately 20 percent of the genetic component of the disease," according to a news release on the finding.
"Describing the genetic underpinnings of any complex disease is a complicated but critical step. By further refining the genetic landscape of multiple sclerosis and identifying novel genetic associations, we are closer to being able to identify the cellular and molecular processes responsible for MS and therefore the specific biological targets for future drug treatment strategies," study researcher Jacob McCauley, Ph.D., of the International Multiple Sclerosis Genetics Consortium and the University of Miami Miller School of Medicine, said in a statement.
Researchers used technology called ImmunoChip to identify the genetic variants. They analyzed DNA from 50,794 healthy people and 29,300 people with multiple sclerosis.
Multiple sclerosis is a condition where the immune system attacks the protective sheath around the nerves, leading to nerve deterioration, according to the Mayo Clinic. Symptoms can vary depending on the severity of the nerve damage. While there is no cure for the condition, treatments can help to slow its progress.
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Republican Presidential candidate Mitt Romney's wife's MS is central to his campaign. They often discuss her 1998 diagnosis, as well as how she <a href="http://abcnews.go.com/Health/ann-romneys-ms-highlights-unpredictable-disease/story?id=16221663#.T99GaytYvJV" target="_hplink">managed the disease while raising five sons</a>, ABC reported. <br><br> But she recently had to take a break from campaigning when her symptoms were aggravated. "I start to almost lose my words. I almost can't think. I can't get my words out. I start to stumble a little bit and so <a href="http://www.etonline.com/news/121147_Ann_Romney_on_Recent_MS_Scare_on_Campaign_Trail/index.html" target="_hplink">those things were happening</a> and I thought, 'Uh oh, big trouble,'" she said in an interview with Entertainment Tonight.
The Daytime Emmy award-winning talk show host announced his diagnosis in 1999, and he started the <a href="http://www.oprah.com/health/Montel-Williams-Battle-with-MS-Overcoming-Depression-and-Pain" target="_hplink">Montel Williams MS Foundation</a> to raise money for research into the disease. <br><br> His <a href="http://www.oprah.com/health/Montel-Williams-Battle-with-MS-Overcoming-Depression-and-Pain/3" target="_hplink">main symptom is pain</a>, he told Dr. Oz on an episode of "Oprah." "I've got pain from my shins to my feet, 24 hours a day, 365 days a year, and it's been there for the last 10 years." Then the pain spread to his face. "It literally feels like you're taking a fork and stabbing me right now. People say, 'How the devil do you deal with this?'" he said. "You have to get a grip."
The Emmy award-winning journalist and husband to Meredith Viera <a href="http://www.usatoday.com/news/health/spotlighthealth/2004-07-07-cohen-spotlight_x.htm" target="_hplink">first learned of his diagnosis in 1973</a>, but was reluctant to speak up about it, he told <em>USA Today</em> in 2004. "I always resisted being defined by my MS," he said. "That's why I was obsessively secretive about it in the early years. It never dawned on me that people thought I had a drinking problem. Police even followed me home a few times thinking I was under the influence."
The comedian was first <a href="http://www.usatoday.com/life/people/2005-12-10-richard-pryor-obit_x.htm" target="_hplink">diagnosed with MS in 1986</a>, and eventually became debilitating enough to drastically affect his work,<em> USA Today</em> reported. <br><br> He died in 2005 of a heart attack at age 65.
The actress, well known for her roles in "Young Frankenstein" and "Close Encounters of the Third Kind" was diagnosed with MS in 1999, <a href="http://www.rd.com/health/actress-terri-garr-battles-multiple-sclerosis/" target="_hplink">after 16 years of symptoms</a> like tingling, tripping and stabbing pain, according to <em>Reader's Digest</em>. <br><br> She <a href="http://www.everydayhealth.com/multiple-sclerosis/teri-garr.aspx" target="_hplink">spoke out publicly about the disease in 2002</a>, according to Everyday Health, becoming a pair spokesperson for an MS medication and a National Ambassador for the National Multiple Sclerosis Society, and advocating for research and education.
The singer and wife of NBA player Grant Hill opened up on "Extra" in 2005 about <a href="http://telepixtvcgi.warnerbros.com/v2/news/0505/27/3/text.html" target="_hplink">her diagnosis nearly two years before</a>. "I went from being physically active to not being able to get out of bed," she said. <br><br> But she knew she had to push through and <a href="http://www.nationalmssociety.org/online-community/personal-stories/tamia/index.aspx" target="_hplink">speak up about the disease</a>, she said. "I just felt it was important to get it out there and let people know it's not a sign of weakness. You have good days and bad days."
The country musician was <a href="http://www.nationalmssociety.org/online-community/personal-stories/clay-walker/index.aspx" target="_hplink">diagnosed in 1996 at the age of 26</a>, according to the National Multiple Sclerosis Society, after losing feeling in his right hand and leg. <br><br> Through mediation, diet and exercise, he has regained feeling, continued on in his music career and worked to raise money and awareness of the disease. He was <a href="http://www.nationalmssociety.org/online-community/personal-stories/clay-walker/index.aspx" target="_hplink">named Ambassador of the Year</a> by the National Multiple Sclerosis Society, only the fourth person to receive the distinction in nearly 60 years.
Alan And David Osmond
Alan, entertainer and producer (and brother to Donny and Marie), noticed he was tripping on nothing while he was on stage in 1987 and was <a href="http://www.nationalmssociety.org/ms-awareness-week/alan-osmond/index.aspx" target="_hplink">diagnosed with MS</a> a few years later, he told the National Multiple Sclerosis Society. <br><br> His son, David, known for his turn on "American Idol," was <a href="http://www.nationalmssociety.org/online-community/personal-stories/david-osmond/index.aspx" target="_hplink">diagnosed in 2006</a>, and says one of Alan's favorite sayings -- "I may have MS but MS does not have me" -- keeps him performing. <br><br> <em>Photo: Left to right: Alan, David and Donny Osmond</em>
The writer, who <a href="http://www.independent.co.uk/life-style/health-and-families/features/lsquothis-is-what-ms-looks-likersquo-2122567.html" target="_hplink">detailed her diagnosis in "The White Album,"</a> told the <em>New York Times</em> she went <a href="http://www.nytimes.com/1979/06/10/books/didion-calif.html?pagewanted=3" target="_hplink">blind for six weeks</a> due to the disease.
The "Real Housewives of Washington D.C." star revealed a <a href="http://www.foxnews.com/entertainment/2010/09/15/exclusive-michaele-salahi-says-multiple-sclerosis/" target="_hplink">17-year battle with MS</a> on a 2010 Fox appearance. She said she hoped to use her fame to help others.
The First Lady <a href="http://news.yahoo.com/blogs/cutline/michelle-obama-letterman-isn-t-oprah-where-laughs-231917424.html" target="_hplink">spoke about her father's multiple sclerosis</a> on a recent episode of "The Late Show With David Letterman." "I never knew him to be able to walk, but my dad worked so hard and he loved us so much," she said. "I think from him I learned just absolute, complete unconditional love, the notion that kids really don't need anything but to know that their parents adore them."
The author's mother passed away in 1991 after a <a href="http://www.people.com/people/article/0,,1147497,00.html" target="_hplink">10-year battle with MS</a>, People.com reported. She said that her greatest regret is that her mother didn't live to see the wild success of Rowling's Harry Potter series.