Pick's disease. Clinical genetics and natural history.

The relatives of 18 probands with neuropathologic evidence of Pick's disease were assessed with the main aim of estimating their risk for dementing illness. Fifteen secondary cases of dementia were discovered among relatives. The risks were significantly greater for probands' first-degree relatives than for second-degree relatives, which suggests an etiologic contribution from genes. Although numbers are small, the distribution of cases and their ages at onset are consistent in suggesting a sex effect, with male subjects more at risk than female subjects.