A study has found that a gene called TOMM40 appears twice as often in people with Alzheimer’s disease than in those without it. Alzheimer’s, for which there is no cure, is the leading cause of elderly dementia.
The image depicts the comparison of a normal aged brain (top) and an Alzheimer’s patient’s brain (bottom). Differential characteristics are pointed out.
With the exception of a gene called ApoE-4, the common genetic risk factors for sporadic Alzheimer’s disease are unknown.
Alzheimer’s disease destroys brain cells, causing problems with memory, thinking and behavior. Alzheimer’s disease is the sixth-leading cause of death in the United States, and it’s estimated that there are as many as 5.3 million Americans living with Alzheimer’s in 2009.
Having the harmful form of TOMM40 significantly increases one’s susceptibility when other risk factors, such as having the ApoE-4 gene, are present. People who have ApoE-4 are three to eight times more likely to develop Alzheimer’s.
“The TOMM40 gene influences the ease with which molecules can get in and out of mitochondria, the energy production center and stress mediator of cells. TOMM40 also processes materials that form amyloid plaque, a hallmark of Alzheimer’s,” said Dr. Steven Potkin, lead author of the study.
“With aging, the number and function of mitochondria decrease, accompanied by a parallel increased risk of developing Alzheimer’s,” he said. “This study points to the use of mitochondrial-based therapies for treating the disease.”
Supporting the discovery is recent research in which scientists found that patients with TOMM40 developed Alzheimer’s an average of seven years earlier than those without the gene.
References:
1. Potkin SG, Guffanti G, Lakatos A, Turner JA, Kruggel F, et al. 2009 Hippocampal Atrophy as a Quantitative Trait in a Genome-Wide Association Study Identifying Novel Susceptibility Genes for Alzheimer’s Disease. PLoS ONE 4(8): e6501. doi:10.1371/journal.pone.0006501.
