Sergey Brin, a Google co-founder, said Thursday that he has a gene mutation that increases his likelihood of contracting Parkinson's disease, a degenerative disorder of the central nervous system that can impair speech, movement and other functions.
Brin, who made the announcement on a blog, says he does not have the disease and that the exact implications of the discovery are not clear. Studies show that his likelihood of contracting Parkinson's disease in his lifetime may be 20 percent to 80 percent, Brin said.
Brin, whose personal fortune was recently pegged at $15.9 billion by Forbes, ranking him as the 13th richest American, said that he may help provide more money for research into the disease.
Through a Google spokesman, Brin declined to be interviewed for this article.
Brin said he learned that he carries a mutation of the LRRK2 gene, known as G2019S. His mother, Eugenia Brin, also carries the gene mutation and has Parkinson's.
Medical experts said that those who carry that gene mutation are more likely than not to live disease-free.
"Many people with this mutation never develop the disease," said Dr. Susan Bressman, chairwoman of the neurology department at Beth Israel Medical Center in New York. "He is more likely to have a normal life than a Parkinson's disease life."
Bressman, who specializes in movement disorders and genetics, said that about 30 percent of people with the gene mutation develop the disease.
Brin said he discovered that he carried the gene mutation using a service from 23andMe, a biotechnology startup co-founded by his wife, Anne Wojcicki. The company can map customers' DNA and help them find information about their ancestry and their risk of getting certain diseases. Google, where Brin is president of technology, invested $3.9 million in 23andMe in May 2007.
Parkinson's disease is typically a late-onset disorder, in which people often first exhibit symptoms in their 50s or 60s. Brin is 35.
Symptoms, which can include tremors, stiffness, slowness of movement and speech impairment, can sometimes be managed through medication and surgery. While many people with the disease continue to function at a high level for many years, the disease is not curable and highly variable. Symptoms tend to become progressively worse over time.
"This leaves me in a rather unique position," Brin wrote in his blog post. "I know early in my life something I am substantially predisposed to. I now have the opportunity to adjust my life to reduce those odds (e.g. there is evidence that exercise may be protective against Parkinson's). I also have the opportunity to perform and support research into this disease long before it may affect me."
Brin and his family have already endowed the Eugenia Brin Professorship in Parkinson's Disease and Movement Disorders at the University of Maryland School of Medicine, where his mother is being treated.
Analysts said they did not believe that the news about Brin would have a negative impact on Google's shares.