Movement Disorder Linked to Faulty Gene
Syndrome Caused by Abnormal Gene May Lead to Balance Problems, Tremors, and Dementia Later in Life
WebMD News Archive
Jan. 27, 2004 -- Men may be carrying a genetic mutation responsible for a significant portion of the movement and mental difficulties they encounter as they grow older.
A new study suggests that this genetic abnormality only becomes apparent in men over 50 and can cause tremors, balance problems, and dementia that become more severe with age.
Researchers say many of the adults that suffer from this disorder, known as fragile X-associated tremor/ataxia syndrome (FXTAS), are misdiagnosed with other age-related conditions such as Parkinson's and Alzheimer's disease.
"FXTAS may be one of the most common causes of tremor and balance problems in the adult population, yet is being misdiagnosed because neurologists who see adults with movement disorders are not aware that they need to look for a family history of fragile X in grandchildren or to check for the presence of the permutation in the fragile X gene," says researcher Randi Hagerman, MD, medical director of the University of California, Davis MIND Institute, in a news release.
What Is FXTAS?
FXTAS affects older men who carry a small mutation in the same gene that causes fragile X syndrome, which is the most common cause of inherited mental retardation.
In the study, published in the Jan. 28 issue of The Journal of the American Medical Association, researchers looked at the prevalence of tremor, balance disorders, and dementia among 192 families belonging to the Northern or Southern California Fragile X Associations.
Researchers say nearly one in 800 men have this mutation in the fragile X gene, and the study suggests that as many as 30% of these men may develop FXTAS later in life.
The study showed that 17% of the men in their 50s had the disorder, but the percentage of men with symptoms, such as tremors and balance problems, increased dramatically with each decade of life. For example, 38% of the men in their 60s, 47% of those in their 70s, and 75% of men in their 80s had these symptoms.
Researchers say the majority of men with the genetic mutation will develop at least mild symptoms of FXTAS.