Identification of TSC1 and TSC2 mutations in Korean patients with tuberous sclerosis complex.

Tuberous sclerosis complex is a genetic disorder caused by mutations in the genes TSC1 or TSC2. Studies of these mutations are very rare in Korean populations. A previous study identified mutations in only 30% of patients by denaturing high performance liquid chromatography with sequencing. Here, we sought to determine the mutational frequency in Koreans. Eleven patients who fulfilled the diagnostic criteria for tuberous sclerosis complex were included. All patients underwent sequencing of both TSC genes, and if no mutations were evident, multiplex ligation-dependent probe amplification was performed. Mutations were detected by sequencing in 82% (9/11) of patients: 36.4% (4/11) in TSC1 and 45.5% (5/11) in TSC2. Two patients with no mutations carried large deletions that included exon 1 of TSC1 in one patient and exons 1-15 of TSC2 in the other patient. Mutations were completely identified in the present study. Therefore, mutation rates in Korean patients may not be lower than those in other ethnic groups. Direct sequencing followed by multiplex ligation-dependent probe amplification analysis may constitute a rational approach to identify disease-causing mutations in Korean patients.