The analysis of mutations and exon deletions at TSC2 gene in angiomyolipomas associated with tuberous sclerosis complex

Abstract

Angiomyolipomas (AMLs) are relatively rare hamartomatous or benign tumors that occasionally occur as part of tuberous sclerosis complex (TSC). Mutations in either of the two genes, TSC1 and TSC2, have been attributed to the development of TSC. Between 1994 and January 2009, 83 patients were diagnosed with AML at the Samsung Medical Center. In that group of patients, 5 (6%) had AML with TSC (AML-TSC). Mutational analysis of the TSC2 gene was performed using 7 samples from the 5 AML-TSC patients and 14 samples from 14 patients with sporadic AML without TSC (AML-non-TSC). From this analysis, mutations in TSC genes were identified in 5 samples from the AML-TSC patients (mutation detection rate=71%) and 3 samples from AML-non-TSC patients (mutation detection rate=21%). In the case of AML-TSC, 6 mutations were found including 3 recurrent mutations and 3 novel mutations, while in the case of AML-non-TSC, 4 mutations were identified once, including 1 novel mutation. Also MLPA analysis of the TSC2 gene showed that TSC2 exon deletion is more frequently observed in AML-TSC patients than in AML-non-TSC patients. This is the first mutation and multiplex ligation-dependent probe amplification (MLPA) analyses of TSC2 in Korean AMLs that focus on TSC. This study provides data that are representative of the distribution of mutations and exon deletions at TSC genes in clinically diagnosed AML-TSC cases of the Korean population.

Keywords: Angiomyolipoma; Exon deletion; Mutation; TSC2 gene; Tuberous sclerosis complex.