Aicardi-Goutières Syndrome (AGS)

What is Aicardi-Goutières syndrome (AGS)?

Aicardi-Goutières syndrome (AGS) is an inflammatory disease that mostly affects the brain, immune system, and skin. It typically appears in the first year of life, usually in the first three months. The exact prevalence of AGS is unknown. It can be difficult to diagnose because many of its symptoms are similar to other conditions’.

What are the symptoms of AGS?

Symptoms usually progress over a course of several months before the disease course starts to stabilize. They include:

Early symptoms: difficulty falling asleep, difficulty feeding, extreme irritability, low grade fever, developmental regression
Severe intellectual and physical disability
Epilepsy
A very small head
Itchy, painful skin lesions
Problems with vision
Stiff joints and muscles
Involuntary muscle movement
Weak muscle tone in the torso
Presence of white blood cells/inflammation in the cerebrospinal fluid (the fluid that surrounds the brain and spinal cord)
Buildup of calcium deposits in the brain

What causes AGS?

Human traits are inherited from a person’s father and mother; each one contributes a copy of a gene, which interacts with the other copy. When a gene mutates, it can lead to disease. There are multiple types of AGS which depend on the gene that causes the condition. Known affected genes are: TREX1, RNASEH2A, RNASEH2B, RNASEH2C, SAMHD1, ADAR and IFIH1 genes. Most cases of AGS are inherited in an autosomal recessive pattern, meaning that both parents need to pass down a copy of the defective gene for the condition to occur. Rare autosomal dominant cases have been reported. In those cases, only one parent needs to pass down a copy of the gene for the condition to occur.

How is AGS diagnosed?

AGS can be diagnosed using the following procedures:

Recording of medical history
Blood tests
Tests of the cerebrospinal fluid (the interferon signature in particular)
MRI and CT scans
Brain ultrasound scan
Specific genetic testing

What are the treatments for AGS?

AGS treatment is supportive, working to treat whatever symptoms each patient has. It can include:

Chest physiotherapy
Drugs to control epilepsy
Work to prevent postural abnormalities
Treatment of lung infections
Regimented diet
Monitoring for evidence of glaucoma, scoliosis, diabetes, and underactive thyroid

Where can I find out more about AGS?