[Clinical characteristics and genetic analysis of a Chinese pedigree affected with tuberous sclerosis complex]

To explore the genetic basis for a Chinese pedigree affected with tuberous sclerosis complex (TSC).

The TSC1 and TSC2 genes were sequenced. Candidate variant was verified by Sanger sequencing of the proband and her family members. Pathogenicity of the variant was predicted based on the American College of Medical Genetics and Genomics (ACMG) guidelines.

The proband was found to harbor a heterozygous c.52delC frameshift variant of the TSC2 gene, which may result in synthesis of amino acid chain starting from the 18th amino acid Leu and terminating at the 28th amino acid (p.Leu18CysfsTer28). The variant was unreported in the public database. Mutation Taster software predicted that the variant is harmful. Both parents of the proband were of the wild type, suggesting that the variant has occurred de novo. Based on the ACMG guidelines, the variant was predicted to be likely pathogenic (PVS1 +PM2).

A novel pathogenic variant of the TSC2 gene c.52delC (p.Leu18CysfsTer28) was identified, which has enriched the mutational spectrum of TSC2 and provided a basis for genetic counseling for this pedigree.