Foliar depigmentation is one of the clinical manifestations of tuberous sclerosis, which is an oval, striated, lobe-shaped hypopigmented spot. Tuberous sclerosis (TSC) is said to be a nodular, usually autosomal dominant neurocutaneous syndrome, and disseminated cases, consisting of ectodermal tissue organ abnormalities, brain, skin, nerve, renal, and multi-organ involvement, clinically characterized by facial sebaceous adenoma, epilepsy, and intellectual disability. The incidence is approximately 1/6000 live births with a male to female ratio of 2:1. What are the causes of lobar depigmentation? Tuberous sclerosis is a genetic disease and can be classified into four types based on genetic localization: TSC1, TSC2, TSC3, and TSC4. Mutations in TSC1 and TSC2 cause abnormalities in the function of the missense and nodular proteins, respectively, affecting their cellular differentiation regulation, which leads to abnormalities in ectodermal, mesodermal, and endodermal cell growth and differentiation. The mode of inheritance is autosomal dominant, with approximately one-third of familial cases, in which the mutated TSC1 or TSC2 gene is inherited from one parent, and approximately two-thirds of disseminated cases, in which patients are born with a newly mutated TSC1 or TSC2 gene and no family member has the disease. Familial patients with TSC1 mutations are more common, while sporadic patients with TSC2 mutations are more common.