Inheritance is autosomal dominant. Some familial cases have cerebellar degeneration as the outstanding feature with relatively mild dementia. The incubation period for intracranial grafts is approximately 18 months, whereas the pituitary cases are as long as 14 years. Fourteen cases of vCJD have now been confirmed in the UK, and one in France. The spectrum has now widened and the oldest patient is 51.
Diagnosis is pathological.
While none of this constitutes proof that vCJD represents BSE in man, the circumstantial evidence is quite compelling. There have not been any cases of vCJD anywhere in the world, with a clinical onset prior to 1994. Only one case of vCJD has occurred outside the UK, even though other countries have much larger collections of CJD brains. The biochemical similarities of transmitted BSE and naturally occurring FSE to vCJD constitute the strongest link, and underline the difference between vCJD and other types. If vCJD represents BSE in humans, further cases are likely to occur in the near future.