In 2013 and 2021, the International TSC Consensus Group reviewed their diagnostic criteria and surveillance and management recommendations, with notable updates pertaining to the inclusion of genetic testing and highlighting the frequency of genetic mosaicism.2,49 The molecular identification of a pathogenic TSC1 or TSC2 variant by the standards of the American College of Medical Genetics is diagnostically sufficient for TSC. This evidence concerns the gene TSC1 and tuberous sclerosis.