High prevalence of Werner's syndrome in Sardinia. Description of six patients and estimate of the gene frequency.

Several patients with Werner's syndrome in a large family group in Sardinia were ascertained three years ago and reported briefly by Rabbiosi and Borroni (1979). Since then two sisters from a second family and a single case from a third family were ascertained. The three families originated from the Northern part Sardinia and no connection between them was found. We provide a detailed clinical description of six of these patients and attempt to estimate the prevalence and the gene frequency of Werner's syndrome in Sardinia. The prevalence was calculated as 1:94,914 for the two districts of Sassari and Nuoro and as 1:202,766 for the whole island. This is the highest prevalence thus far ascertained. Using Dahlberg's formula we obtained an estimate of the gene frequency q = 0.003288 and thus a frequency of Werner's syndrome of 1:92,515. A more rigorous estimate gave a gene frequency q = 0.001483 and thus a frequency of Werner's syndrome of 1:454,505, but because of the small sample size this estimate should be taken with caution.