Researchers develop first antibody that detects gene mutations that cause amyotrophic lateral sclerosis

Researchers at the University of Toronto's Faculty of Medicine have developed the first antibody that detects the only known cause of amyotrophic lateral sclerosis (ALS), also called Lou Gehrig's disease.

ALS is a progressive and usually fatal neurological disorder that attacks the nerves and muscles. Currently there is no known cure or effective treatments. The latest findings, published in the online edition of Nature Medicine on May 7th, are significant as they provide the world's first tool for recognizing misfolded conformations of the enzyme superoxide-dimutase-1 (SOD1). Mutations in the gene encoding SOD1 cause approximately one to two per cent of all ALS cases.

“This antibody will enable researchers to investigate whether misfolded SOD1 is involved in other forms of ALS,” said Professor Janice Robertson (Laboratory Medicine and Pathobiology) Canada Research Chair in the Molecular Mechanics of ALS at the Centre for Research in Neurodegenerative Diseases, and one of the lead authors of the study. “This is important to determining if SOD1 is relevant in ALS cases that are not caused by mutations in SOD1. If this is the case, then the antibody could potentially be used in biomarker studies to facilitate earlier diagnosis of the disease.”

The antibody, named SOD1-exposed-dimer-interface antibody (SEDI-antibody), also opens up the possibility of developing immunization strategies for the treatment of ALS caused by SOD1 mutations, according to Professor Avi Chakrabartty (Medical Biophysics and Biochemistry, Ontario Cancer Institute – University Health Network), senior author of the study. “The SEDI antibody also has utility in drug discovery efforts for identifying chemical chaperones that prevent or reduce misfolding of SOD1 in ALS ,” said Chakrabartty .

Over 114 mutations have been identified and it is not yet known how so many different mutations result in the same disease, while the normal enzymatic function of SOD1 is not affected. Approximately 3,000 Canadians currently live with ALS, which causes complete paralysis and death usually within two to five years.

The research was funded by the Neuromuscular Research Partnership of the Canadian Institutes of Health Research, the ALS Society of Canada and the Muscular Dystrophy Association of Canada; the ALS Association (US), the Motor Neurone Disease Association (UK) and the Temerety Family Trust.

The study will be published in the June print edition of Nature Medicine .