TSC2 and tuberous sclerosis: We employed a series of techniques using next generation sequencing (NGS) to identify mutations in TSC1 and TSC2. DNA samples from 53 subjects with TSC and no mutation identified (NMI) by prior studies were studied, including DNA derived from blood and/or saliva from 52 patients, one sample from a fetus who died of TSC complications, and 10 biopsies of TSC skin lesions.