Makindo Medical Notes

Nearly all known cases of Aicardi syndrome are sporadic, meaning they are not inherited and occur in individuals with no family history of the disorder. The condition almost exclusively affects females and is rare in males, likely because it is often lethal in males.

About

• Aicardi syndrome is a rare genetic disorder that affects brain development and eye structure.
• It is sporadic in nature, meaning it occurs randomly without being passed down through families.
• Almost exclusively affects females, with very few male cases reported, likely due to the X-linked nature of the disorder being lethal in most males.

Aetiology

• Aicardi syndrome is believed to be caused by mutations on the X chromosome. It is an X-linked dominant disorder, which explains why it predominantly affects females.
• Characterized by complete or incomplete absence of the corpus callosum, the structure that connects the two hemispheres of the brain.
• The specific gene involved has not been definitively identified, but it is thought that mutations in genes responsible for brain development play a critical role.

Clinical Features

• Neurological symptoms:
  • Severe intellectual disability.
  • Infantile spasms (a type of seizure seen early in life) and other seizure types.
  • Microcephaly (small head size) due to abnormal brain development.
  • Structural brain abnormalities, including absence or thinning of the corpus callosum.
• Ophthalmologic features:
  • Chorioretinal lacunae: distinctive lesions in the retina that can lead to visual impairment or blindness.
  • Other retinal problems, such as colobomas (gaps or holes in eye structures).
• Physical features:
  • Facial abnormalities, such as a shortened philtrum (the area between the nose and upper lip) and a flat nasal bridge.
  • Small hands and short stature.
• Developmental issues: Severe delays in physical and cognitive milestones, with limited motor skills and speech abilities.

Investigations

• CT/MRI: Imaging studies confirm the absence or deficiency of the corpus callosum, along with other structural brain abnormalities.
• Ophthalmologic exam: Retinal abnormalities can be detected with specialized eye exams.
• Genetic testing: Can be performed to investigate the presence of mutations related to the syndrome, though the exact gene involved has not been clearly identified.

Management

• Seizure control: Anti-epileptic medications are necessary to manage infantile spasms and other seizures.
• Supportive care: Multidisciplinary care including physical therapy, occupational therapy, and speech therapy to support developmental needs.
• Vision care: Regular ophthalmologic exams and interventions as necessary for visual impairments.
• Surgical interventions: May be necessary for complications such as scoliosis or other physical abnormalities.
• Genetic counseling: Important for families to understand the sporadic nature of the disorder and the low risk of recurrence in future pregnancies.

Prognosis

• The prognosis for Aicardi syndrome varies depending on the severity of symptoms, particularly seizure control and the degree of brain involvement.
• Most individuals experience significant intellectual and physical disabilities, but life expectancy can be highly variable.

References

• Aicardi syndrome - Genetics Home Reference
• Aicardi Syndrome - NIH Rare Diseases