A 30-year-old man thought to have died in January from vCJD belonged to a genetic group that had not shown any signs of the disease, scientists say.

In the UK, 166 people have died of variant CJD, linked to eating BSE-infected beef, and all were thought to have shared a certain gene.

Writing in the Lancet, the scientists say Grant Goodwin, of Lanarkshire, had a different version of the gene.

They estimate that up to 350 people in this group could get vCJD.

Scientists have always thought that a second wave of vCJD cases would emerge some time after the first.

This is the first indication that this theory is being born out with the identification of the first probable vCJD patient outside of the initial genetic group, BBC science correspondent Pallab Ghosh reports.

Thomas Goodwin believes his son Grant was incubating the disease for much of his life

It is probable because the diagnosis is based on observations of the progression of the disease rather than post-mortem tests which would have provided absolute confirmation of the disease, he adds.

The case report written by Professor John Collinge, of the National Prion Clinic, and colleagues is a reminder that the disease has not gone away.