AGS; Aicardi Goutieres Syndrome; Cree Encephalitis; Encephalopathy with Basal Ganglia Calcification; Familial Infantile Encephalopathy with Intracranial Calcification and Chronic Cerebrospinal Fluid Lymphocytosis; Pseudotoxoplasmosis Syndrome; Pseudo-TORCH Syndrome

Aicardi-Goutieres Syndrome (AGS) is a rare genetic neurodevelopmental disorder characterized by encephalopathy (brain dysfunction) that affects newborn infants and usually results in mental and physical disability. The severe early-onset form affects approximately 20 percent of infants born with AGS and is usually fatal within the first few months of life.

Diagnostic testing: The diagnosis of AGS is established by:

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  Reports of genetic testing of mutations in one of five known related genes (TREX1, RNASEH2A, RNASEH2B, RNASEH2C);

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  Head CT showing calcification of basal ganglia and white matter +/- atrophy; or

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  Magnetic resonance imaging (MRI) showing leukodystrophy.

Physical findings: The signs and symptoms of AGS may include:

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  Microcephaly;

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  Peripheral spasticity (weak or stiffened muscles) ;

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  Truncal hypotonia (decreased muscle tone);

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  Poor head control;

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  Dystonia (involuntary muscle contractions that cause repetitive or twisting movements);

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  Characteristic painful itchy, red skin lesions (chilblains) on hands, feet, and ears; and

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  Profound intellectual disabillity.

Children with the early-onset form of AGS may have:

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  Neurological deficits;

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  Hepatosplenomegaly (enlarged liver and spleen); and

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  Elevated liver enzymes that may mimic congenital viral infection.

Children with later-onset AGS begin having symptoms after the first weeks or monhs or normal development. Then, they may experience:

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  Moderate to severe developmental delay;

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  Seizures;

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  Extreme irritablity;

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  Inconsolable crying;

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  Intermittent fever;

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  Loss of developmental skills;

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  Visual impairment; and

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  Joint stiffness.

ICD-9: 348.9

The prognosis of AGS depends upon the severity of symptoms and signs, and the age of onset.

SUGGESTED PROGRAMMATIC ASSESSMENT*

Suggested MER for Evaluation:

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  Clinical history and examination that describes the diagnostic features of the impairment;

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  Imaging studies such as MRI/CT brain scans documenting brain abnormalities;

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  Molecular genetic studies and cerebrospinal fluid analysis; and

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  EEG results (if history suggests seizures).

Suggested Listings for Evaluation:

REMARKS