The Egyptian Journal of Neurology, Psychiatry and Neurosurgery (Nov 2022)
Glycine encephalopathy
Abstract
Abstract Inherited neurotransmitter diseases are a subset of rare neurometabolic disorders characterized by hereditary deficiencies in neurotransmitter metabolism or transport. Non-ketotic hyperglycinaemia (NKH), called glycine encephalopathy, is an autosomal recessive glycine metabolism disorder characterized by an abnormal accumulation of glycine in all bodily tissues, including the CNS. The SLC6A9 gene, which codes for the GLYT1 protein, a biochemical abnormality in the GCS, and dihydrolipoamide dehydrogenase enzymes, which function as a GCS component, are responsible for the neonatal form’s symptoms, which include progressive encephalopathy, hypotonia, seizures, and occasionally mortality in the first few days of life. By changing the MAPK signalling pathways, glycine deprivation in the brain damages neurons by increasing NMDA receptor activation, increasing intracellular Ca levels, and leading to DNA breakage and cell death in the neuron region. In addition to the previously mentioned clinical diagnosis, NKH or GE would be determined by MLPA and 13C glycine breath tests. Pediatricians, surgeons, neurologists, and geneticists treat NKH and GE at the newborn period; there is no cure for either condition.
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