Scientists at Massachusetts General Hospital, the University of Massachusetts and Kings College in London found the mutation by doing detailed sequencing of the genes in several families with an inherited form of ALS. The findings are published in the February 27 issue of the journal Science and were partially funded by the ALS Association.

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He was then transferred to Kings College Hospital in south London, where he spent more than a month in a serious condition.

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The researchers - drawn from several universities including Cambridge, Oxford and Kings's College in London - said the findings should be used to reassure smokers attempting to quit that concerns about increased anxiety levels were unfounded.

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