Researchers have discovered that a certain type of enzyme plays a key role in the advance of Lou Gehrig's disease, raising the chances of delaying the progress of the chronic, usually fatal muscle disorder.

The researchers from the Institute of Physical and Chemical Research, based in Wako, Saitama Prefecture, focused on the role of the caspase-9 enzyme in the disease, formally known as amyotrophic lateral sclerosis, according to the EMBO Journal, a publication of the European Molecular Biology Organization.

ALS is a chronic, progressive disease marked by gradual degeneration of the nerve cells in the central nervous system that control voluntary muscle movement. The disorder results in muscle weakness and atrophy. Its cause is unknown.

ALS patients suffer difficulty breathing and need to use a respirator two to five years after the disorder develops.

A report carried in the journal says the group's "data strongly suggest that caspase-9 plays a crucial role in disease progression of ALS and constitutes a promising therapeutic target."

The group's findings are based on data collected from experiments on transgenic ALS mice models, during which the researchers blocked the function of one of the 14 types of caspase.

The mice that suffered ALS died an average of 25 days after the disorder developed, but blocking caspase-9 increased the period to an average of 35 days.

Group leader Ryosuke Takahashi said controlling all forms of caspase may lead to adverse side effects, but targeting just one kind could lead to an effective cure.

Caspases are important in apoptosis, or programmed cell death, which is significant in eliminating unwanted cells during tissue regeneration and other biological processes.