Tuberous sclerosis Health Article

Definition

Tuberous sclerosis is a group of two genetic disorders that affect the skin, brain/nervous system, kidneys, and heart, and cause tumors to grow. The diseases are named after a tuber- or root-shaped growth in the brain.

Alternative Names

Adenoma sebaceum

Causes, incidence, and risk factors

Tuberous sclerosis is inherited. Changes (mutations) in two genes, TSC1 and TSC2, are responsible for the condition.

Only one parent needs to pass on the mutation for the child to get the disease. However, most cases are due to new mutations, so there usually is no family history of tuberous sclerosis.

This condition is one of a group of diseases called neuro-cutaneous syndromes. Both the skin and central nervous system (brain and spinal cord) are involved.

There are no known risk factors, other than having a parent with tuberous sclerosis. In that case, each child has a 50% chance of inheriting the disease.

Symptoms

Skin symptoms include:

• Café-au-lait spots
• Red patches on the face containing many blood vessels (adenoma sebaceum)
• Raised patches of skin with an orange-peel texture (shagreen spots), often on the back
• White areas of skin that look like an ash leaf (ash leaf spots)

Brain symptoms include:

• Developmental delays
• Mental retardation
• Seizures

Other symptoms:

• Heart tumors (rhabdomyoma)
• Kidney tumors
• Pitted dental enamel
• Rough growths under or around the fingernails and toenails
• Rubbery non-cancerous tumors on or around the tongue

The symptoms of tuberous sclerosis vary from person to person. Some people have normal intelligence and no seizures. Others have severe retardation, serious tumors, or difficult-to-control seizures.

Signs and tests

Signs may include:

• Abnormal heart rhythm (arrhythmia)
• Calcium deposits in the brain
• Non-cancerous "tubers" in the brain
• Rubbery growths on the tongue or gums
• Tumor-like growth (hamartoma) on the retina, pale patches in the eye
• Tumors

Tests may include:

• CT scan of the head
• MRI of the head
• Ultrasound of the kidney
• Ultraviolet light examination of the skin

DNA testing for either of the two genes that can cause this disease (TSC1 or TSC2) is available.

Regular ultrasound checks of the kidneys are an important screening tool, to make sure there is no tumor growth.