GENETIC INTERPRETATION OF HEIGHTENED RISK OF BSE IN OFFSPRING OF AFFECTED DAMS

An analysis is presented of the results of a cohort study designed to test whether or not the aetiological agent of bovine spongiform enceph alopathy (BSE) in cattle can be transmitted maternally (vertically) fr om dam to offspring. Various genetic models are fitted to the data und er the assumption that the results could be explained entirely by gene tic predisposition to disease (as opposed to maternal transmission) gi ven exposure of offspring of diseased and unaffected dams to contamina ted cattle feed. The analyses suggest that the results could be explai ned by the hypothesis of genetic predisposition, provided a large diff erence exists in the susceptibility of resistant and susceptible hosts , and explore the ranges of genotypic parameters and frequencies consi stent with the limited currently available data. The results presented are broadly robust, even under the scenario that a portion of the obs erved maternally enhanced risk of BSE is due to a low level of materna l transmission in late incubation stage dams.