Aicardi Syndrome
What is it?
Aicardi syndrome is a rare disorder that was first identified in 1965 by a French neurologist named Dr. Jean
Aicardi. Children with this disorder are either partially or completely missing the nerve fibers, called the corpus
callosum, that link the two hemispheres of the brain. This symptom is usually accompanied by infantile spasms (seizures), mental retardation, and growths, called lacunae, on the retina or optic
nerve.
Who gets it?
Aicardi syndrome affects only females. Researchers have identified only between 300 and 500 cases of Aicardi syndrome
worldwide.
What causes it?
The exact cause of Aicardi syndrome is not currently known. However, researchers believe it is an X-linked genetic disorder that occurs because of a random, unpredictable mutation. In simple terms, chromosomes are thread-like structures that carry genes and help to pass on genetic information. When a gene mutates, it undergoes a sudden structural change that results in a new characteristic or trait not originally found in the parent gene. The X chromosome is one of two chromosomes that determine an individual's sex. Males have an X and a Y chromosome, while females have two X chromosomes. Defects that are X-linked appear on the X chromosome only, and not the Y. Researchers have connected Aicardi syndrome to the X chromosome because it occurs only in females. It is not a hereditary
condition.
What are the symptoms?
Infants with Aicardi syndrome may have an apparently normal birth, but begin to develop symptoms between the ages of 3 and 5 months. At this age, important stages in normal brain development cannot occur because of the missing or incomplete corpus callosum that allows the right side of the brain to communicate with the left. Because of this, the infant begins to have infantile spasms, which is a type of seizure. Other symptoms that are definite hallmarks of Aicardi syndrome include mental retardation and growths, called lacunae, on the retina of the eye. Retinal lacunae can cause blindness. Other types of brain defects, such as microcephaly (small brain), porencephalic cysts (cerebrospinal fluid-filled cavities or gaps in the brain where there should be healthy brain tissue), and enlarged ventricles, may also be present.
How is it diagnosed?
Females are diagnosed with Aicardi syndrome, usually between the ages of three months and five months, when infantile spasms alert the parents and healthcare provider to a disorder. A computed tomography (CT) scan or magnetic resonance imaging
(MRI) of the head will show any abnormalities with the corpus
callosum, cysts, or enlarged ventricles. The doctor may also order an electroencephalogram (EEG), which measures the electrical activity in the brain and helps to identify types of seizures. An eye exam will reveal any growths on the retina. The combination of female sex, seizures, abnormalities with the corpus
callosum, and retinal lacunae provide a definite diagnosis of Aicardi syndrome. In some cases, the corpus callosum may look normal, but other abnormal formations in the brain are
present.
What is the treatment?
There is no cure or standard treatment for Aicardi syndrome. Treatment is specific to the symptoms, and usually involves medication to manage seizures and early intervention programs for developmental
delays.
Self-care tips
While the prognosis for Aicardi syndrome does not appear good, continuing genetic research aims to find the cause of and a treatment for this disorder. If your child has Aicardi syndrome, you may find it helpful to seek the support of the Aicardi Syndrome Foundation, which can keep you up-to-date on the most recent findings.
This information has been designed as a comprehensive and quick reference
guide written by our health care reviewers. The health information written
by our authors is intended to be a supplement to the care provided by your
physician. It is not intended nor implied to be a substitute for
professional medical advice.
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