Select the most common clinical sign or symptom for diagnosis Tuberous sclerosis

Tuberous sclerosis, an autosomal dominant condition, can result in severe mental retardation and seizures. Infantile spasms, a hypsarrhythmic EEG pattern, hypopigmented lesions (ash-leaf spots), cardiac tumors, sebaceous adenomas, a shagreen patch (a roughened, raised lesion over the sacrum), and calcifications on the CT scan are all features of this condition. No specific treatment is available.