Prevalence of Tuberous Sclerosis Complex in Taiwan: A National Population-Based Study

BACKGROUND/AIMS: Tuberous sclerosis complex (TSC) is an autosomal dominant disorder caused by mutations in the TSC1 and TSC2 genes. Previous studies have estimated the prevalence of TSC to be 1:8,000 to 1:30,000. The numbers of patients and the populations accessed in these studies are relatively small. The aim of this study is to evaluate the prevalence of TSC in Taiwan with a population of 23 million people. METHODS: 95% of Taiwanese are enrolled in a single national health insurance database. This study uses this database to estimate the prevalence of TSC in a large Chinese population. RESULTS: The prevalence of TSC in Taiwan is estimated at 1:95,136. There is no prevalence difference in rural or urban areas. The ages of the patients ranges from 3 months to 75 years, with a mean of 14 +/- 11 years. Prevalence by age is 1:14,608, 1:18,851, and 1:24,617 for ages <6, 12, and 18 years, respectively. Only 15% of patients disclose a family history of TSC. The majority of cases (71.2%) are diagnosed in an outpatient visit by a pediatrician. CONCLUSION: The low prevalence of TSC in Taiwan might result from differences in penetrance, family planning, ethnic groups, and disease-modifying genes.