Role of mutational analysis in diagnosis of tuberous sclerosis complex.

We describe three cases in whom identification of a disease-causing mutation in the TSC1 or TSC2 gene preceded the appearance or detection of symptoms sufficient for a clinical diagnosis of tuberous sclerosis complex (TSC). We suggest that genetic testing be given a more prominent role in the evaluation of individuals with a family history of TSC or symptoms suggestive of TSC and propose that diagnostic criteria be revised to include genetic testing.