Familial or sporadic clusters of presenile dementia in Scotland

Abstract

Between 1974 and 1988, discrete areas within Scotland had unexpectedly high incidences of presenile Alzheimer's disease. To examine whether these clusters might be attributable to 'familial' cases occurring in the same locality, we performed a case-control study of parental cause of death entered on death certificates. Cases comprised (1) 145 presenile Alzheimer's disease patients and (2) 73 vascular dementia patients presenting in Lothian between 1974 and 1988. Two control individuals per case, of the same sex, born in the same registration district, and whose fathers had the same occupation as the case's father, were chosen from birth registration data. Parental death certificates for 131 presenile Alzheimer's disease and 65 vascular dementia cases were located. There was no significant association detected between a diagnosis of presenile Alzheimer's disease and dementia as a parental cause of death (p = 0.25), nor for vascular dementia (p = 0.67). Presenile Alzheimer's disease cases were less likely to have a parent die with cerebrovascular disease (chi 2 = 4.80, p < 0.05) and vascular dementia cases more likely to have a parent die with cerebrovascular disease (chi 2 = 5.28, p < 0.05). There was no increased incidence of other vascular disease or bronchogenic carcinoma in cases' parents compared with control individuals' parents.