Clean-up gene gone awry can cause Lou Gehrig’s disease

Mutations on a gene necessary for keeping cells clean can cause Lou Gehrig’s disease, scientists report online March 24 in Nature Neuroscience. The gene is one of many that have been connected to the condition.

In amyotrophic lateral sclerosis, also known as Lou Gehrig’s disease, nerve cells that control voluntary movement die, leading to paralysis. Scientists have previously identified mutations in 29 genes that are linked with ALS, but these genes account for less than one-third of all cases.

To track down more genes, a team of European researchers looked at the protein-coding DNA of 252 ALS patients with a family history of the disease, as well as of 827 healthy people. The team discovered eight mutations on a gene called TBK1 that were associated with ALS.

TBK1 normally codes for a protein that controls inflammation and cleans out damaged proteins from cells. “We do not know which of these two principle functions of TBK1 is the more relevant one” to ALS, says coauthor Jochen Weishaupt, a neurologist at Ulm University in Germany. In cells with one of the eight TBK1 mutations, the protein either is missing or lacks components that it needs to interact with other proteins, the researchers found.

TBK1 mutations may explain 2 percent of ALS cases that run in families, which make up about 10 percent of all incidences of the disease, Weishaupt says.