20 years later.

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.