ScienceDaily (Dec. 25, 2011) — A global team of neuroscientists, led by researchers at Mayo Clinic in Florida, has found the gene responsible for a brain disorder that may be much more common than once believed. In the Dec. 25 online issue of Nature Genetics, the researchers say they identified 14 different mutations in the gene CSF1R that lead to development of hereditary diffuse leukoencephalopathy with spheroids (HDLS). This is a devastating disorder of the brain's white matter that leads to death between ages 40 and 60. People who inherit the abnormal gene always develop HDLS. Until now, a definite diagnosis of HDLS required examination of brain tissue at biopsy or autopsy.
The finding is important because the researchers suspect that HDLS is more common than once thought and a genetic diagnosis will now be possible without need for a brain biopsy or autopsy. According to the study's senior investigator, neurologist Zbigniew K. Wszolek, M.D., a significant number of people who tested positive for the abnormal gene in this study had been diagnosed with a wide range of other conditions. These individuals were related to a patient known to have HDLS, and so their genes were also examined.
"Because the symptoms of HDLS vary so widely -- everything from behavior and personality changes to seizures and movement problems -- these patients were misdiagnosed as having either schizophrenia, epilepsy, frontotemporal dementia, Parkinson's disease, multiple sclerosis, stroke, or other disorders," says Dr. Wszolek. "Many of these patients were therefore treated with drugs that offered only toxic side effects.
"Given this finding, we may soon have a blood test that can help doctors diagnose HDLS, and I predict we will find it is much more common than anyone could have imagined," he says.