Genetics, genomics, and genotype–phenotype correlations of TSC : Insights for clinical practice

Tuberous Sclerosis Complex (TSC) is a multisystem autosomal dominant condition caused by inactivating pathogenic variants in either the TSC1 or the TSC2 gene, leading to hyperactivation of the mTOR pathway. Here, we present an update on the genetic and genomic aspects of TSC, with a focus on clinical and laboratory practice. We briefly summarize the structure of TSC1 and TSC2 as well as their protein products, and discuss current diagnostic testing, addressing mosaicism. We consider genotype–phenotype correlations as an example of precision medicine, and discuss genetic counseling in TSC, with the aim of providing geneticists and health care practitioners involved in the care of TSC individuals with useful tools for their practice.