Tuberous sclerosis is an autosomal dominant neurocutaneous disease which is caused by mutation in the TSC1 or TSC2 gene. Tuberous sclerosis affects almost every organ system of the human body. One of the cutaneous manifestations of tuberous sclerosis is ash leaf spots. These are hypopigmented macule. Reference: https://step1.medbullets.com/neurology/113051/tuberous-sclerosis Image via: https://step1.medbullets.com/neurology/113051/tuberous-sclerosis