Study: Genetics May Play Larger Role In Who Develops ALS

LOS ANGELES (CBSLA.com) — Genetics may play a larger role in causing ALS, also known as Lou Gehrig's disease, than previously believed, according to research at Cedars-Sinai Medical Center.

Typically, researchers classify 90 percent of ALS cases as sporadic, meaning they occur in patients without a family history of the disease.

The Cedars-Sinai study found genes could account for more than a third of cases. They found that patients with defects in two or more ALS-associated genes saw the onset of the disease approximately 10 years earlier than patients with single-gene mutations.

Investigators at Cedars and Washington University in St. Louis partnered for this study, which shed light on the genetics behind ALS, especially in patients who had no family history of the disease, said Dr. Robert H. Baloh, director of neuromuscular medicine in the Department of Neurology and director of the ALS Program at Cedars-Sinai.

Researchers examined the DNA from 391 patients and identified many new or very rare mutations among 17 genes already known to be tied to ALS.

Baloh, the senior author of the study, said the mutations do not necessarily cause the disease  — but they are likely suspects, and, when combined, might increase a person's chances for developing the disease.

Amyotrophic Lateral Sclerosis is a progressive neurodegenerative disease that affects nerve cells in the brain and the spinal cord, which control muscle movement.

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