CJD is one of the Transmissible Spongiform Encephalopathy (TSE) that affect man (human, homo sapien), the others are Kuru, Gerstmann Straussler Scheinker syndrome (GSS) and Fatal Familial Insomnia (FFI).

Other examples of TSEs are Bovine Spongiform Encephalopathies (BSE, mad cow disease, cattle), Scrapie (sheep, goats), Chronic Wasting Disease (CWD, CWDD, mule deer, white-tailed deer, black-tailed deer, elk), Feline Spongiform Encephalopathy (FSE, cats), Transmissible Mink Encephalopathy (TME, mink), Transmissible Spongiform Encephalopathy of Captive Wild Ruminants ( eland, Arabian oryx, greater kudu, gemsbok, nyala, scimitar horned oryx, ankole, bison).

Summary of Prion Diseases and transmission

Disease	Host	Mechanism of Pathogenesis
Kuru	Human beings	Infection through ritualistic cannibalism
Gerstmann Straussler Scheinker syndrome(GSS)	Human beings	Germ-line mutations in PrP gene
Fatal Familial Insomnia (FFI)	Human beings	Germ-line mutations in PrP gene
Sporadic Familial Insomnia (SFI)	Human beings	Spontaneous conversion of PrPC to PrPSc
Iatrogenic CJD (iCJD)	Human beings	Infection from prion-contaminated human growth Hormone (hGH),dura mater grafts etc
Variant CJD (vCJD)	Human beings	Infection from bovine prions
Familial CJD (fCJD)	Human beings	Germ-line mutations in PrP gene
Sporadic CJD (sCJD)	Human beings	Somatic mutations, or spontaneous conversion of PrPC to PrPSc
Scrapie	Sheep, Goats	Infection in genetically susceptible sheep
Bovine Spongiform Encephalopathy (BSE)	Cattle	Infection with prions from sheep or cattle
Transmissible Mink Encephalopathy (TME)	Mink	Infection with prions from sheep or cattle
Chronic wasting disease	Mule deer, White-tailed deer, Black-tailed deer, Elk	Unknown
Feline spongiform encephalopathy	Cats	Infection with prion-contaminated bovine tissues or meat and bone meal
Exotic ungulate encephalopathy	Eland, Arabian oryx, Greater kudu, Gemsbok, Nyala, Scimitar horned oryx, Ankole, Bison	Infection with prion-contaminated meat and bone meal

TSEs are degenerative disorders of the central nervous system (CNS) and brain that lead to motor dysfunction, dementia, and death.

The exact mechanisms for transmission are yet unknown, however normal prion protein, PrP or PrPc (a ubiquitously expressed protein) undergoes conversion to an abnormal prion protein termed PrPsc. The sc designation means scrapie but other labels such as cjd, and res have been used to describe the abnormal form.

PrPsc accumulates in the brain and amyloid like aggregates are visible upon histological analysis. These aggregates are associated with the appearance of large patterns of vacuolation. The vacuolation indicates neuronal cell death and the pattern makes the tissue resemble a sponge like appearance.

The samples we have available are human brain and spleen homogenates from sporadic CJD (sCJD, spCJD) sources, new variant CJD (vCJD, nvCJD) sources and control (clinically non-CJD, normal, ctrl) sources and 16-20 amino acid long peptides (synthesised fragments of the prion protein). We also have available limited quantities of sheep (ovine) scrapie and cow (bovine) BSE brain, spleen, blood and blood components. We are also in the process of developing other resources (and making available reference materials) to facilitate research into this area.

These brain samples and spleen samples have been characterised (so far) by Immunoblot (Western Blotting), ELISA, DNA sequencing, Protein Assay and STR. Other diagnostic and characterisation tests are currently undergoing investigation.

Some of the brain samples are now classed as CJD brain reference standards by the WHO (World Health Organisation) after collaborative studies. Other samples are due to or are currently undergoing collaborative study evaluation.