American and Canadian scientists have shown for the first timethat chromosome 21 (C-21) contains a gene for inheritedamyotrophic lateral sclerosis.

More than half of the 23 independent families surveyedshowed a link between ALS and markers on the long arm of C-21.

ALS, also known as Lou Gehrig's disease, is a motor neurondisease that leads to nerve and muscle degeneration and deathwithin five years. About six per 100,000 people in the UnitedStates have ALS. Of those, only 5 to 10 percent have aninherited form.

The researchers caution that the linkage must be verified, asdoes Dr. P. Michael Conneally of Indiana University, author ofan editorial that accompanied the paper in today's New EnglandJournal of Medicine. Conneally noted that the linkage of ALS toC-21 can lead to the isolation of a defective gene. In the future,therapies may target both inherited and non-inherited forms,which have similar symptoms.

The finding that not all inherited forms of ALS are linked to C-21 suggests the involvement of other genes. InheritedAlzheimer's disease, which maps to either C-21 or C-19, alsoapparently is due to more than one gene defect.

The collaborators, led by Duke University scientists, includedresearchers from Northwestern University, McGill University,the Massachusetts Institute of Technology and MassachusettsGeneral Hospital. Funding came from Cambridge NeurosciencesResearch Inc., as well as the National Institutes of Health, andassociations representing ALS and muscular dystrophyinterests.

-- Carol Talkington Verser, Ph.D. Special to BioWorld

(c) 1997 American Health Consultants. All rights reserved.