Tuberous sclerosis

Definition:

An inheritable disorder characterized by skin lesions, varying degrees of mental retardation, and seizures.

Causes, incidence, and risk factors:

Tuberous sclerosis is inherited as an autosomal dominant trait. It is one of a group of diseases described as neurocutaneous syndromes because of extensive involvement of both the skin and the central nervous system (brain and/or spinal cord). The symptoms of tuberous sclerosis, however, vary considerably from minimally affected people with normal intelligence and no seizures to severely affected people with profound retardation and frequent, difficult-to-control seizures. The disease is named after the typical brain lesion which is called a tuber.

Severely affected people may develop seizures shortly after birth that are characterized by infantile spasms (hypsarrhythmia). Later seizures tend to be myoclonic. Mental retardation becomes evident as infants begin to miss their normal developmental milestones.

Several different skin lesions are common in tuberous sclerosis.

• "Ash leafs" are depigmented or hypopigmented (lacking normal skin color) white lesions that have the shape or appearance of an ash leaf and may appear anywhere on the body.
• Shagreen patches: These appear on the lower back as raised patches of skin with an orange-peel texture.
• adenoma sebaceum: These lesions include red, highly vascular, lumps on the face that may resemble irritated acne. These enlarge with age and may run together (become confluent) to form larger patches.