Researchers at Northwestern University say they have discovered a common cause behind the mysterious and deadly affliction of amyotrophic lateral sclerosis, or Lou Gehrig's disease, that could open the door to an effective treatment, according to the Chicago Tribune.

Dr. Teepu Siddique, a neuroscientist with Northwestern's Feinberg School of Medicine whose pioneering work on ALS over more than a quarter-century fueled the research team's work, said the key to the breakthrough is the discovery of an underlying disease process for all types of ALS.

The Northwestern team identified the breakdown of cellular recycling systems in the neurons of the spinal cord and brain of ALS patients that results in the nervous system slowly losing its ability to carry brain signals to the body's muscular system. Without those signals, patients gradually are deprived of the ability to move, talk, swallow and breathe.

"This is the first time we could connect (ALS) to a clear-cut biomedical mechanism," Siddique said. "It has really made the direction we have to take very clear and sharp. We can now test for drugs that would regulate this protein pathway or optimize it, so it functions as it should in a normal state."

There were 23 contributing scientists, including the lead authors, Northwestern neurological researchers Han-Xiang Deng and Wenjie Chen, and Siddique as senior author.

ALS afflicts about 30,000 Americans. With no known treatment for the paralysis, 50% of all ALS patients die within three years.

A variety of proteins perform different functions within cells, and Deng and Chen led research that discovered a key protein, ubiquilin2, in the ALS mystery.

Ubiquilin2 in spinal and brain system cells is supposed to repair or dispose of other proteins as they become damaged. The researchers discovered a breakdown of this function in ALS patients.

When Ubiquilin2 is unable to remove or repair damaged proteins, the damaged proteins begin to pile up in the cells, eventually blocking normal transmission of brain signals in the spinal cord and brain, leading to paralysis.