Lou Gehrig's disease, or amyotrophic lateral sclerosis, is a debilitating neurological condition causing progressive muscle weakness and disability. According to the National Institute of Neurologic Disorders and Stroke, more than 90 percent of all Lou Gehrig's disease cases occur among people with no obvious risk factors. However, a small percentage of people are at known risk of developing the disease due to certain genetic defects and dietary and demographic factors.
Family History
A genetic defect passed down through families is a known risk factor for the inherited form of Lou Gehrig's disease called familial amyotrophic lateral sclerosis, or FALS. According to the Mayo Clinic, children of individuals with this disease have a 50 percent chance of developing the condition themselves. The FALS genetic defect is located on chromosome 21, and it impairs the functioning of the superoxide dismutase enzyme, which is responsible for protecting motor neurons from cellular damage, according to NeurologyChannel.com. Researchers know that there are additional genetic defects involved in Lou Gehrig's disease, but they have not yet been able to identify them.
Neurotoxin Exposure
Dietary exposure to an amino acid neurotoxin called BMAA is a risk factor for a variation of Lou Gehrig's disease that primarily develops among the people of Guam. According to NeurologyChannel.com, residents of Guam used to eat and make flour with the tropical plant called Cycas circinalis. The seeds of this plant contain a chemical that is poisonous to the nervous system and can lead to the development of Gaumanian ALS.
Glutamate
While the vast majority of people who develop Lou Gehrig's disease seem to have no risk factors, emerging research suggests that a malfunctioning immune system caused by a chemical imbalance may underlie some of these cases. According to NeurologyChannel.com, the chemical messenger glutamate is vital in regulating brain and nerve function. A review in the November 2005 issue of the Journal of Neurochemistry finds additional evidence to suggest that glutamate acts as a signaling agent, stimulating both the immune system and the nervous system. Elevated levels of glutamate can cause the immune system to overreact and attack healthy cells, while also over-stimulating and destroying motor neurons. Additional research is needed to clarify the role of glutamate in increasing the risk of Lou Gehrig's disease.
Demographic Factors
Individuals belonging to certain demographic groups are at higher risk of developing Lou Gehrig's disease. According to the Mayo Clinic, individuals ages 40 to 60, those who have served in the military and those living in parts of Japan and West New Guinea are more likely to develop ALS. Women are also at higher risk of developing Lou Gehrig's than men until age 65, at which point men are just as susceptible as women.
References
- Neurology Channel: ALS/Lou Gehrig's Disease Risk Factors
- Mayo Clinic: Amyotrophic Lateral Sclerosis Risk Factors
- Journal of Neurochemistry; Emerging Evidence for a Similar Role of Glutamate Receptors in the Nervous and Immune Systems; Boldyrev AA et al.; November 2005
- National Institute of Neurologic Disorders and Stroke: ALS--Who Gets It?
