Human form of mad cow disease identified in new genetic group

New genetic information about the human version of mad cow disease (vCJD) has heightened concerns in Britain that there are more carriers of the fatal disease than originally thought.

According to the BBC, scientists say a 30-year-old man Grant Goodwin, who is believed to have died of vCJD earlier this year, belonged to a genetic group that had not shown any signs of the disease.  While 166 people have died in Britain of vCJD, scientists estimate that up to 350 people in this genetic group could get vCJD.

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

The findings are expected to renew calls in Britain to begin routine blood screening for vCJD.  Mississauga, Ont.-based Amorfix Life Sciences (TSX:AMF) has developed the first highly-sensitive and accurate blood screening test for vCJD that is now nearing the regulatory finish line in Britain and the rest of Europe.

vCJD is caused by infectious agents called prions.  Tests showed that Mr. Goodwin had a heterozygous version of the gene, which codes for the human prion amino acids valine (V) or methionine (M).  People can be V V (homozygous), M M (homozygous) or M V (heterozygous).

Since 1994, around 200 cases of vCJD have been identified worldwide, and all those tested have been M M homozygous.  Mr. Goodwin was M V heterozygous, however.

It is thought that 47% of the British population have this version of the gene.  ”If individuals with other genotypes are similarly susceptible to developing prion disease after BSE prion exposure, but with longer incubation periods, further cases would be expected,” Prof. Collinge warned.