title: 20 years later.
abstract: A systematic review of the biochemical troubles associated with Trisomy 21 lead to three constatations: 1) There must be an important perturbation of the oxygen metabolism (Excess of S.O.D.I. and of G.P.X.) 2) There is probably a shift in the regulation of non essential amino acids (Comparison with other forms of mental deficiencies) 3) In conformity with a general hypothesis, an abnormality of the monocarbon metabolism could be the consequence of 1) and 2) and could represent the actual cause of mental deficiency.
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D002794:Choline / Q000378:metabolism; D004314:Down Syndrome / Q000235:genetics / Q000378:metabolism*; D005979:Glutathione Peroxidase / Q000378:metabolism; D006038:Glyoxylates / Q000378:metabolism; D006801:Humans; D008607:Intellectual Disability / Q000209:etiology; D010101:Oxygen Consumption; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D000596:Amino Acids; D006038:Glyoxylates; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D002794:Choline