By Koushani Das, Farooq Ali Khan, Abhishek Kumar, Raamesh Gowri Raghavan, and Sukant Khurana:
A rare genetic malformation syndrome, termed as Aicardi Syndrome or familial infantile encephalopathy was first described by in 1961 by Jean Francois Aicardi, a French pediatrician. It is found exclusively in young female population and rarely in males with Klinefelter’s syndrome having XXY type chromosome. This disease is inherited in an autosomal recessive manner.
Effects
Dysgenesis of corpus callosum, that is, complete absence of tissue connecting the left and right side of the brain, asymmetry between two sides of the brain, reduced brain folds and grooves , enlargement of fluid-filled cavities, microcephaly (small head) , chorioretinal lacunae, that is, defects in the retina, Scoliosis (abnormal curvature of the spine), gastrointestinal problems like constipation and diarrhea accompanied by severe epilepsy are the foremost symptoms of this rare disease. This neurological disorder is characterized by infantile spasms in young children less than one year of age and is generally fatal.
Occurrence And Initial Symptoms
- Symptoms of this disease appear within first six-months of life.
- The initial symptoms include vomiting, unusual facial features, feeding difficulties and lack of motor and social skills
- Aicardi Syndrome is caused by mutation in any of the 6 genes named as TREX1, RNASEH2B, RNASEH2A, RNASEH2C, SAMHD1, ADAR.
Diagnosis/Testing
Increased level of interferon gamma and lymphocytes support the diagnosis of Aicardi syndrome[1].
Differential diagnosis in Aicardi syndrome that is:
- Measurement of lactic and pyruvic acid in blood and cerebrospinal fluid to exclude the presence of mitochondrial encephalopathy.
- Measurement of lysosomal enzymes on leukocytes to exclude leukodystrophies, is generally carried out to exclude the presence of other neurological pathologies [2]
- Ophthalmological examination and magnetic resonance imaging ( MRI) are used to detect chorioretinal lacunae and gross cerebral symmetry respectively. Transfontanellar ultrasonography in the neonatal period is the gold- standard examination to detect some features of this rare disease since it is cheap and has higher accuracy compared to MRI testing.
- Anti epileptic drugs (AED) , like vigabatrin can be supplied to patients to control adequate seizures. Physical therapies including the use of splints can help to prevent contractures. Injections of Botulinum Toxin (Botox), currently available at $382 in U.S.A, by American Society of Plastic surgeon[4], is sometimes required for this ailment. Patients also benefit from tube-feeding.
- Patients with Aicardi Syndrome should be regularly screened for treatable condition, most probably glaucoma and endocrine problems like hypothyroidism.
Post Mortem Finding
A post mortem finding on Aicardi Syndrome (July- August, 1989) published by Pediatric Neurology, Vol 5, by Shin Ichiro Hamano says that , a female infant at about 5 yrs of age when subjected to a pathological examination, revealed cortical heterotopias, hypoplasia of optic nerve and cavum septum pellucidum .
Case Studies/Reports
A 1-month year old girl was suspected with ocular malformations including an anterior chamber cyst in one eye which was surgically removed.
A rare occurrence in a 15 month year old female child with regular features of Aicardi Syndrome , a tumor was located at the left ventricular atrium (choroid plexus papilloma).
Until 2014, at least 400 cases have been known which include rarely two cases in males having 47 chromosomes.
Social Media Exposure
Aicardi Syndrome Foundation, is a volunteer-based nonprofit organization which works to raise funds, supports family and awareness towards Aicardi Syndrome .
Journey and real life stories of Aicardi affected children can be visited on this website. Below is an example.
“ Addie is now almost 10 years old! She has come so far! When diagnosed at 5 months, we were told she would never walk or talk. She now has accomplished both! She attends a therapeutic public school. She says “no cool” every morning as she’d rather stay home than go to school! As you can see we are working on her /s/ blends!
She loves music, swinging and all things Disney and is a happy, shining star in our eyes!”
Ongoing Studies
At Baylor College of Medicine, scientists or researchers have been looking for genetic changes that may be the cause of Aicardi Syndrome with the help of a new method, microarray-based comparative genomic hybridization (array-CGH). This technique involves a DNA chip, the size of a microscope slide, with hundreds of thousands of small pieces of DNA attached to it.
University of California, San Francisco (UCSF) is currently investigating and working on the genetic disorders of the brain development that affect the corpus callosum as in Aicardi Syndrome.
Prevention
Aicardi Syndrome is a problem of probability and Manchester NIHR Biomedical Research Centre is currently working after this rare disease . There are no known ways to prevent Aicardi Syndrome as no specific genetic mutation has been implicated in Aicardi syndrome.
References
1. neuropathology of Aicardi syndrome (European journal of pediatric neurology) — Peter G Barth
2. Differential Diagnosis– Department of child neurology and psychiatry,University of Pavia, by Giovanni s
Dr. Sukant Khurana runs an academic research lab and several tech companies. He is also a known artist, author, and speaker. You can learn more about Sukant at www.brainnart.com or www.dataisnotjustdata.com and if you wish to work on biomedical research, neuroscience, sustainable development, artificial intelligence or data science projects for public good, you can contact him at skgroup.iiserk@gmail.com.