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Aicardi-Goutieres syndrome (AGS) is a rare genetic condition marked by the early onset of severe neurological issues, such as intellectual incapacity, mobility difficulties, and developmental delay. It is brought on by mutations in one of many genes involved in the synthesis of proteins that are important for DNA metabolism and the immune system.

Aicardi–Goutières Syndrome :‎ [MEDNOTES+MINDMAP]

  • Definition

    • Aicardi-Goutières Syndrome (AGS) is a rare, inherited neurological disorder characterized by brain inflammation and damage to the brain and nervous system.
  • Epidemiology

    • AGS is a rare disorder, with an estimated incidence of 1 in 500,000 live births.
    • It is more common in males than females.
    • It can occur in any racial or ethnic group.
  • Natural history

    • AGS typically presents in the first few weeks of life with symptoms such as fever, irritability, and difficulty feeding.
    • Over time, individuals with AGS may experience developmental delays, intellectual disability, and seizures.
    • The severity of AGS can vary greatly, with some individuals experiencing mild symptoms and others experiencing severe, life-threatening complications.
  • Types:

    • AGS can be classified into three main types based on the genetic mutation present: 
    • Type 1 AGS is caused by mutations in the RNASEH2A, RNASEH2B, or RNASEH2C genes.
    • Type 2 AGS is caused by mutations in the SAMHD1 gene.
    • Type 3 AGS is caused by mutations in the TREX1, ADAR, or IFIH1 genes.
  • Risk Factors

    • Genetic mutations in the TREX1, RNASEH2A, RNASEH2B, or RNASEH2C genes
    • Family history of Aicardi-Goutières Syndrome
  • Etiology/Causes

    • Mutations in the TREX1, RNASEH2A, RNASEH2B, or RNASEH2C genes, which are responsible for DNA repair and RNA metabolism
    • Environmental factors such as viral infections or exposure to toxins
  • Signs

    • Delays in physical and cognitive development
    • Seizures
    • Microcephaly (abnormally small head size)
    • Calcification in the brain
    • Chorioretinitis (inflammation of the retina)
    • Increased white matter in the brain
  • Symptoms

    • Poor feeding and weight gain
    • Irritability and abnormal crying
    • Lack of eye contact
    • Failure to thrive
    • Developmental delays
  • Pathology/Pathogenesis

    • The mutations in the TREX1, RNASEH2A, RNASEH2B, or RNASEH2C genes lead to a build-up of abnormal DNA and RNA in the brain, resulting in inflammation and brain damage.
    • This inflammation and brain damage lead to the signs and symptoms of Aicardi-Goutières Syndrome.

Diagnosis

  • Clinical presentation of symptoms
  • Genetic testing to confirm diagnosis

Tests Required

  • Complete blood count
  • Erythrocyte sedimentation rate
  • C-reactive protein
  • Liver function tests
  • Renal function tests
  • Lactic acid
  • CSF analysis
  • MRI of the brain

Associated with:

  • Autoimmune diseases
  • HIV infection
  • Inborn errors of metabolism
  • Environmental factors (exposure to toxins or radiation)

Similar diseases/syndromes

  • Cockayne syndrome
  • Dyskeratosis congenita
  • Neurodegeneration with brain iron accumulation

Treatment

  • Supportive care for symptoms
  • Immunoglobulin therapy
  • Antiviral therapy (if associated with HIV)
  • Treatment for underlying cause (if known)

Dr. Arin Nandi

Passionate About Medical Science & Helping Future Doctors Achieve Top Ranks In Medical Exams. He is professionally a dentist as well as a public health expert from JIPMER working in govt.health department
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