Tuberous sclerosis: a new estimate of prevalence within the Oxford region.

Within the counties administered by the Oxford Regional Health Authority (population 2 328 100) the prevalence of tuberous sclerosis was estimated as 1 in 29 900 for persons under 65 years of age. For the population below 30 years of age the prevalence was 1 in 21 500 and for children under 5 years 1 in 15 400. Cases were ascertained through the records of the Department of Medical Genetics at Oxford and the Tuberous Sclerosis Association of Great Britain and also by a questionnaire sent to selected consultants within the region. A previous estimate of prevalence within the region was 1 in 100 000. This study suggests that the prevalence at birth might be even higher than 1 in 15 000.