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Achromic Patch

See Retinal Achromic Patch.

Adenoma Sebaceum

See Facial Angiofibroma.


See Attention Deficit Hyperactivity Disorder.

Adrenocorticotropic Hormone (ACTH)

Adrenocorticotropic hormone is an antiepileptic medication shown to be effective in treating children with TSC who are suffering from infantile spasms.


See Antiepileptic Drug.


See Angiomyolipoma.


Amniocentesis is a prenatal diagnostic test in which a small amount of amniotic fluid is collected from the uterus for genetic testing. The test is usually performed between 16 and 20 weeks of gestation and involves inserting a fine needle into the uterus to draw a sample of the amniotic fluid.


See Facial Angiofibroma.

Angiomyolipoma (AML)

Angiomyolipoma (AML)
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An angiomyolipoma is a benign tumor that can occur in multiple organs, including the kidney, adrenal gland, liver, ovary, and pancreas. In TSC they are most commonly associated with the kidney. The name of these tumors refers to their composition: an abnormal collection of blood vessels (angio), smooth muscle (myo), and fat (lipoma).

Antiepileptic Drug (AED)

An antiepileptic drug is a medication prescribed to help control seizures. Also known as an anticonvulsant drug.

Ash Leaf Spot

See Hypomelanotic Macule.


Asymptomatic means showing or causing no obvious symptoms.

Atonic Seizure

An atonic seizure is an abnormal discharge of electrical activity in the brain that causes sudden, uncontrolled relaxation of most or all muscles in the body. Atonic seizures may result in what experts generally refer to as drop attacks, in which an individual suddenly collapses or is thrown to the ground.

Attention Deficit Hyperactivity Disorder (ADHD)

Attention deficit hyperactivity disorder is a neurobehavioral disorder that makes learning and social interactions difficult, even for those with normal cognitive abilities, by causing individuals to be easily distracted and frustrated, fidgety, impulsive, and forgetful.


Autism is a neurological disorder of the brain that may result in difficulties with communication and social interaction as well as repetitive behaviors. Autistic traits vary in severity. Also known as autism spectrum disorder.

Autosomal Dominant

Autosomal dominant means that only one copy of a gene, inherited from either the mother or the father, needs to have the mutation for the child to have the disorder. All of the chromosomes except the sex chromosomes are autosomes.

Bayley Scales of Infant Development

The Bayley Scales are diagnostic tests that measure the motor skills, mental development, and behavior of infants from birth to 15 months.

Benign Tumor

A benign tumor is a noncancerous growth that does not spread to other parts of the body. Benign tumors can cause problems, however, depending on the number of tumors, where they grow, and the rate of growth.

Cardiac Rhabdomyoma

Cardiac Rhabdomyoma
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A cardiac rhabdomyoma is a benign tumor of the heart. Rhabdomyomas are composed of tissue normally present in the heart (rhabdo), that grows in a disorganized mass (myoma).


A cardiologist is a physician who is trained and certified to treat problems of the cardiovascular system, including the heart, arteries, and veins. Children may see a pediatric cardiologist.

Chorionic Villi Sampling

Chorionic villi sampling is a method of prenatal diagnosis in which a small piece of fetal placenta, or chorionic villi, is removed early in pregnancy for genetic testing.


click to enlarge photograph

Chromosomes are structures located in the nucleus of the cell that contain our genetic material (genes). Humans have 23 pairs of chromosomes: half of each pair is inherited from our mother, and the other half from our father.

Computed Tomography (CT)

Pulmonary Computed Tomography (CT)
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Computed tomography is a procedure that uses x-rays and computer technology to produce cross-sectional images of the body that are more detailed than traditional x-ray images. Also known as a CAT scan.

Confetti Skin Lesions

Confetti skin lesions are small, lightly pigmented spots 1-2 mm in diameter.


Congenital refers to a condition that is present at birth.

Cortical Tuber

Cortical Tuber
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A cortical tuber is a region of the brain that develops abnormally. These lesions are benign tissue growths that displace normal tissue growth possibly contributing to neurological problems such as seizures, and learning and behavioral issues. Tuberous sclerosis complex is named after these growths. Also known as tuber.


Cryosurgery (also called cryotherapy) is the use of extreme cold to freeze and destroy abnormal tissue, such as lesions or growths on the skin. For external tumors, liquid nitrogen (or argon gas) is applied directly to the cells with a cotton swab or spraying device.


See Computed Tomography.


A cyst is a closed sac of air, fluid or semisolid material. Cysts can occur in multiple organs, including the kidneys, lungs, adrenal glands, liver, ovaries and pancreas.

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This content was last reviewed on March 30, 2006.