Various single-gene mutation disorders are linked to an augmented risk of developing autism spectrum disorder and include fragile X (FMR1), Rett Syndrome (MECP2), Timothy syndrome (CACNA1C), Angelman syndrome (UBE3A), and tuberous sclerosis (either TSC1 or TSC2) [10,11]. The gene discussed is TSC2; the disease is tuberous sclerosis.