Amyotrophic lateral sclerosis was named after the New York Yankee baseball player who died from the disease in 1941.

Doctors at the University of Kentucky, led by Assistant Professor Haining Zhu, reported that mutations in the gene that makes superoxide dismutase 1 slow down the intracellular transport of molecules in neurons and may lead to the death of these neurons.

In an article to be published in Friday's Journal of Biological Chemistry, Zhu demonstrates the molecular mechanism for the defective transport in the disease. In ALS, motor neurons that control voluntary muscles die, leading to muscle weakness and atrophy.

About one-fourth of the familial forms of ALS have been linked to the mutation in the gene that makes superoxide dismutase 1.

Zhu's work clarifies how the defective variants of the superoxide dismutase 1 protein may interact with other cellular components to cause the disease. It is unknown, however, how the transport process is compromised.