Remarkably, the same gene has been found to cause these two different and independent syndromes, affecting different groups of individuals. Fragile X syndrome is a developmental disorder beginning in childhood, while the newly identified neurological syndrome (Fragile X Associated Tremor/Ataxia Syndrome, or FXTAS) affects mainly male carriers who were not affected by fragile X syndrome retardation, and who displayed no symptoms prior to age 50.
"We discovered that FXTAS-affected individuals have numerous inclusions, or spherical particles, in their brain cells," noted study author Paul Hagerman, MD, PhD, professor of Biological Chemistry at the University of California Davis School of Medicine. Through this study, the researchers are determining what is in the inclusions and why they form. "We believe this finding is an important clue as to the cause of the disorder, one that may ultimately help with development of therapies for both the tremor disorder and fragile X syndrome."
Currently, male carriers of the gene do not know they are carriers unless there is an affected grandchild in the family. This is how the researchers have discovered the cases studied to date. Affected individuals have thus far been given other, descriptive diagnoses, such as "atypical Parkinson disease," and have in many cases seen multiple neurologists in their efforts to diagnose their condition.
"We hope that one of the positive outcomes of our investigations will be a greater awareness within the adult neurology community as to the presence of this disorder. Heightened awareness may also lead to better family counseling prior to the birth of children affected with fragile X syndrome," concludes Hagerman.
This study is supported by grants from the National Institute of Neurological Disorders and Stroke and the National Institute of Child Health and Development.
The American Academy of Neurology, an association of more than 18,000 neurologists and neuroscience professionals, is dedicated to improving patient care through education and research. For more information about the American Academy of Neurology, visit its online press room at www.aan.com/press/index.cfm.
Editor's Note: Dr. Hagerman will present the research at the AAN's 55th Annual Meeting in Honolulu during a poster presentation on Thurs., April 3 at 3 p.m. in Kamehameha 1 and 11 at the Hawaii Convention Center (HCC). Dr. Hagerman will be available to answer media questions during a briefing on Wed., April 2 at 2 p.m. in the AAN Press Room, Room 327 of the HCC.
All listed times are for Hawaiian-Aleutian Standard Time (HT).