ABSTRACT. Tuberous sclerosis complex (TSC) is an autosomal dominant neurogenetic disorder characterized by hamartomas in multiple organs and is caused by a wide spectrum of mutations in 1 of 2 causative genes (TSC1 or TSC2). Here, we present mutational analyses of the TSC1 and TSC2 genes in 4 cases of TSC in Chinese Han children, including 2 familial and 2 sporadic cases, using PCR and DNA sequencing of the entire coding region as well as exon-intron boundaries of these genes. Three mutations were identified in the TSC2 gene. Of these mutations, 2 mutations (c.3312-3313delGA and c.45delT) were novel, and the 3rd mutation (c.5238-5255del) was previously reported in Chinese Han and other populations. These mutations were not present in healthy family members or in 100 unrelated normal controls. The identification of these mutations in this study further expands the spectrum of known TSC2 gene mutations and contributes to prenatal molecular diagnosis and preimplantation genetic testing of TSC.