A breakdown in a recycling mechanism in cells in the brain and spinal cord has been pinpointed as the common cause of all forms of amyotrophic lateral sclerosis (ALS), the tragic neurogenerative disorder known as Lou Gehrig's disease.

The problem lies in a system that recycles the building blocks of proteins inside neurons, according to the discovery, reported in the journal Nature on Sunday.

The breakdown occurs in hereditary and non-hereditary forms of ALS, as well as a form of the disease that targets the brain, known as ALS/dementia.

More specifically, the finger of blame points at a worker chemical called ubiquilin2, whose job is to help recycle faulty or damaged proteins in the neurons.

When ubiquilin2 does not work, junk parts of proteins build up in the cell, causing it to be badly damaged.

The research "opens up a whole new field for finding an effective treatment for ALS," said Teepu Siddique, a professor of neurology at Northwestern University in Chicago, in a press release.

"We can now test for drugs that would regulate this protein pathway or optimize it, so (that) it functions as it should."

ALS affects around 350,000 people around the world, many of them young adults in the prime of life.

Patients progressively lose muscle strength, eventually becoming paralysed and unable to speak, move, swallow, or breathe. The illness is named after the star U.S. baseball player Lou Gehrig, who died from the disease in 1941.

Copyright AFP