Conjugal Alzheimer's disease: is there an increased risk in offspring?

Thirty-one couples in which both spouses had the clinical diagnosis of Alzheimer's disease (AD) (confirmed by autopsy in 12) were ascertained. The mean age of onset of dementia was 75.1 +/- 7.4 years. These couples had 87 children, 63 still living. Seventeen (19.5%) of the children developed dementia, with a mean age of onset of 68.9 +/- 8.3 years. Thirty of the children of the conjugal AD couples survived to age 65 or longer and 14 (47%) of them developed dementia. This prevalence of dementia in the children of affected couples is much greater than that in the children of two control groups consisting of 234 couples in which one spouse had AD and 192 couples in which neither spouse was demented. Twenty-one of the conjugal AD couples had a family history of AD but the prevalence of dementia in their children was not greater than that in the children of conjugal AD couples without a family history of AD. These results represent additional evidence of an important genetic component in late-onset AD and provide empirical risk data for the children of conjugal AD couples.