Aicardi syndrome is an uncommon malformation syndrome characterized by
absence of a key structure in the brain called the corpus callosum, the
presence of retinal abnormalities, and seizures in the form of infantile spasms. Aicardi syndrome is inherited as an X-linked
dominant trait that is lethal in males.
History
This disorder was first recognized as a distinct syndrome in 1965 by Jean Aicardi, a French neurologist. A review article by
Dr. Aicardi (Aicardi J, Aicardi syndrome: old and new findings, Int Pediatr. 1998;14(1):5-8) describes the syndrome. Aicardi
syndrome should not be confused with Aicardi-Goutières syndrome, a distinct disorder.
Epidemiology
Around 500 cases of Aicardi syndrome have been reported worldwide. Except that the syndrome is fairly uncommon, its precise
frequency in the population is unknown.
Genetics
Almost all reported cases of Aicardi syndrome have been in females. The few males that have been identified with Aicardi
syndrome have proved to have 47 chromosomes including an XXY sex chromosome
complement, a condition called Klinefelter syndrome.
Aicardi syndrome appears to be lethal in normal males who have only one X chromosome
(and a Y chromosome). In other words, Aicardi syndrome appears to be inherited in an
X-linked dominant pattern due to a mutant gene on the X
chromosome that is lethal in XY males.
All cases of Aicardi syndrome are thought to be due to new mutations. No person with Aicardi
syndrome is known to have transmited the X-linked gene responsible for the syndrome to the next generation.
Features
Children are most commonly identified with Aicardi syndrome between the ages of three and five months. A significant number of
these girls are products of normal births and seem to be developing normally until around the age of three months, when they
begin to have infantile spasms. The onset of infantile spasms at this age is due to closure of the final neural synapses in the
brain, a stage of normal brain development.
Diagnosis
Aicardi syndrome is characterized by the following triad of features:
- Partial or complete absence of the corpus callosum in the brain (agenesis of the corpus callosum);
- Eye abnormalities known as "lacunae" of the retina that are quite specific to
this disorder; and
- The development in infancy of seizures that are called infantile spasms.
Other types of defects of the brain such as microcephaly, porencephalic cysts and enlarged cerebral ventricles due to
hydrocephalus are also more common in Aicardi syndrome.
Treatment
Treatment of Aicardi syndrome primarily involves management of seizures and early/continuing intervention programs for
developmental delays.
Additional complications sometimes seen with Aicardi syndrome include porencephalic
cysts and hydrocephalus, and gastro-intestinal problems. Treatment for prencephalic
cysts and/or hydrocephalus is often via a shunt or endoscopic fenestration of the cysts, though some require no treatment.
Placement of a feeding tube, fundoplication, and surgeries to correct hernias or other
gastrointestinal structural problems are sometimes used to treat gastro-intestinal issues.
Prognosis
The prognosis varies widely from case to case. However, all individuals reported with
Aicardi syndrome to date have experienced developmental delay of a significant degree, typically resulting in moderate to
profound mental retardation. The age range of the individuals reported with Aicardi
syndrome is from birth to the mid 40’s.
References
GeneReviews: Aicardi Syndrome
Phenotype and Management of
Aicardi Syndrome: New Findings from a Survey of 69 Children
Neurology India: Aicardi syndrome: A report of five Indian cases
Aicardi Syndrome:
Old and New Findings
External Links
Support Organizations
Aicardi Syndrome Foundation Support and
information for families caring for children with Aicardi Syndrome.
A.A.L Syndrome d'Aicardi
Sindrome di Aicardi
Current Research
UCSF Brain Development Research
Program
Baylor Department of Molecular and Human
Genetics
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