Most patients with tuberous sclerosis complex (TSC) suffer from epilepsy, and many have cognitive and behavioral problems like severe intellectual disability, autism, and hyperactivity. Only rare patients with TSC and autism have a normal intelligence quotient. We report a 13-year-old girl with definite TSC who had early-onset severe epilepsy, autistic behavior, and moderate developmental delay. By school age, however, she had normal intelligence; her intelligence quotient was at least 70 based on a Stanford-Binet test that she refused to complete. She showed good reading, writing, and language comprehension skills, and the special abilities of hyperlexia, hypermnesia, and hypercalculia. However, she did not speak. Criteria of the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, and her Childhood Autism Rating Scale score of 36 indicated mild to moderate autism. She had severe electroencephalographic abnormalities: hypsarrhythmia, multifocal or generalized epileptiform discharges, and electrical status epilepticus during sleep, with a continuous left temporal focus. Magnetic resonance imaging showed many cortical tubers in all brain lobes, and subependymal nodules. We discuss possible explanations for her lack of speech. Considered as speech apraxia, her mutism could be either a symptom of her TSC or a component of her autism. Another possibility is that long-lasting electrical status epilepticus during sleep led to her autistic behavior and language arrest. Still another possibility is that a disinhibited mammalian target of rapamycin (mTOR) pathway was at the root of all of her neuropsychiatric symptoms.