Glycine encephalopathy is an inherited metabolic disease characterized by abnormally high levels of an amino acid called glycine. Glycine is a chemical messenger that transmits signals in the brain.[4193][4587] According to the symptoms the disease onset, glycine encephalopathy may be divided in:[14076][4587]
Glycine encephalopathy is caused by changes (mutations) in the AMT, GLDC or GCSH genes which result in a deficiency of the enzyme that break-up the glycine. Diagnosis is based in the symptoms, the high glycine levels and the enzyme deficiency, as well as genetic testing. Inheritance is autosomal recessive.[4587][4193] Treatment may include sodium benzoate to reduce the levels of glycine, N-methyl D-aspartate (NMDA) receptor site antagonists, anti-seizure drugs and ketogenic diet.[4193] About half of the babies with the classic form, die within a few weeks of life and the survivors may have motor delay, very small head, seizures and stiffness. In the transient form symptoms may improve with time.[14076]
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