- Last Updated on 14 December 2016
Aicardi Syndrome (AS) represents a disorder characterized by the following triad of clinical features:
- Infantile Spasms
- Absence of the corpus callosum (the principal connection between the right and left halves of the brain)
- Chorioretinal lacunae (abnormalities in the retina, the light-sensitive tissue located at the back of the eye)
In addition, AS is typically associated with neurodevelopmental impairment, with cognitive challenges as well as motor impairment (hypotonia or “low muscle tone” is most common).
Although it is generally rare, AS is a common cause of infantile spasms. It is believed to result from a defect (genetic mutation) on the X-chromosome. Aicardi syndrome exclusively affects girls, with the exception of rare cases in boys with an extra X chromosome (Klinefelter syndrome). The exact gene(s) responsible for AS have not yet been identified, though this is an active focus of current research. Nearly all known cases of AS are "sporadic," which means that they are not passed down through generations and occur in children with no history of the disorder in their family. Because of a process called X-inactivation, in which one of the two X-chromosomes is inactivated in a given brain or retinal (eye) cell, there is considerable variability in the severity of disease among affected children.
Whereas some children suffer catastrophic neurodevelopmental impairment, others may exhibit considerably milder problems—so much so that many children with AS are never diagnosed because they do not exhibit the severe symptoms described in medical texts. There is no specific treatment for AS. The absence of the corpus callosum and retinal abnormalities cannot be fixed, though infantile spasms can certainly be treated. There are indeed several reports in the scientific literature indicating that vigabatrin (Sabril®) is especially effective in AS. This can be difficult choice given the potential for irreversible retinal injury as a result of vigabatrin use.
For additional information and resources, please see the Aicardi Syndrome Foundation.