ESTIMATION OF THE PROPORTION OF GENETIC CASES IN LATE-ONSET DISEASES - AN APPLICATION TO ALZHEIMERS-DISEASE

In diseases with a complex etiology including a genetic component, an important issue is to determine the proportion of cases really having inherited the disease. This is not easy in late-onset diseases where c ensoring might obscure the transmission pattern of the disease and giv e an apparently non-genetic distribution of the cases. We present a mo del that allows the estimation of the proportion of genetic cases in l ate-onset diseases. This model takes censoring into account by explici t modelling of the time dependency of the onset of the disease. The mo del is illustrated with an example based on an epidemiological survey in Alzheimer's disease and with simulated data.