What is Aicardi Syndrome?
Aicardi Syndrome is an extremely rare genetic condition which hampers the development of Corpus Callosum in the brain. In children with Aicardi Syndrome, the Corpus Callosum is either underdeveloped or is totally missing. This condition is almost always seen in newborn girls. Th Corpus Callosum is a structure that connects the two hemispheres of the brain. Aicardi Syndrome is not believed to be an inherited condition but a condition developed during pregnancy.
There is no known cause for Aicardi Syndrome but it is believed to be caused by mutation in the child's genes. Since Aicardi Syndrome is almost always seen in girls hence the mutation is believed to take place in the X chromosome which the females have two in number whereas males have only one X chromosome.
Children with Aicardi Syndrome will have frequent seizures as infants and lesions in the light sensitive tissue layer which is behind the eye. Some children with Aicardi Syndrome may have additional abnormalities of the brain, eyes, and the face, although the severity of the symptoms of Aicardi Syndrome is variable and differ from person to person.
What are the Causes of Aicardi Syndrome?
As stated above, the root cause for Aicardi Syndrome is not yet established but is believed to occur due to a defect in the X chromosome due to the fact that this condition is mostly found in newborn girls. Under normal circumstances, people have 46 chromosomes of which two are sex hormones which are X chromosome and the Y chromosome. These chromosomes help identify whether a child will be a girl or a boy, as girls will have two X chromosome and a boy will have one X and one Y chromosome.
During normal development of embryo, there is one active X chromosome in each cell meaning that one of the X chromosome in a female gets deactivated during development of the embryo but in Aicardi Syndrome this second X chromosome does not get deactivated and is termed as skewed X-inactivation.
What are the Symptoms of Aicardi Syndrome?
The symptoms of Aicardi Syndrome are normally seen in females between the ages of 2 and 6 months old. The child may have infantile spasms which may later go on to full blown seizures. There may also be yellowish spots in the eyes. These spots are caused due to lesions in the light sensitive layers of tissue present behind the eye normally caused by Aicardi Syndrome. Some of the other symptoms of Aicardi Syndrome are:
- Presence of a coloboma, a hole or gap in one of the structures of the eye
- Abnormally small eyes
- Deformities of the hands
- Intellectual impairments
- Developmental delays and failure to reach milestones on time
- Problems with feeding
- Diarrhea alternating with constipation
- Gastroesophageal reflux
Additionally, children with Aicardi Syndrome may have symptoms of spine and rib abnormalities like a scoliosis. They may also have unusual facial structure like a flat nose or large ears. Some children with Aicardi Syndrome may also have vision impairment.
How is Aicardi Syndrome Diagnosed?
The diagnosis of Aicardi Syndrome is normally based on the symptoms experienced by the child but since each child may present with different symptoms thus further diagnostic studies to confirm the diagnosis of Aicardi Syndrome needs to be done. This is done in the form of:
- Ophthalmic examination to check for lesions behind the eyes
- EEG to check for electrical activity in the brain
- An MRI or CT scan of the brain which will give clinching evidence of an underdeveloped or a missing Corpus Callosum thus confirming the diagnosis of Aicardi Syndrome.
How is Aicardi Syndrome Treated?
As of now, there is no cure for Aicardi Syndrome. The treatment is basically symptomatic and supportive. The first and the foremost method of treatment is to control the seizures caused due to Aicardi Syndrome. This is done by utilizing antiepileptics. Children with intellectual disabilities may be sent to special education so that they can be trained to do certain basic activities to make them somewhat independent. The child may also be evaluated by a neurologist along with speech therapy and occupational therapy to make them as independent as possible.
What is the Life Expectancy for Aicardi Syndrome?
Coming to life expectancy from Aicardi Syndrome, children with this disorder tend to have a short life span but again this depends on the severity of the disease and how much the child is affected by the symptoms.
Almost all children with Aicardi Syndrome will have some type of intellectual disability. In some cases, a few percent of children learn to speak in few sentences and walk independently but in majority of cases the child will require support for the whole life to carry out activities due to Aicardi Syndrome.