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Updated: Aug 19, 2026

Chromosome Preparation From Cultured Cells
Published on: January 28, 2014
[Amino acids and trisomy 21]
J Lejeune1, M O Rethoré, M C de Blois
1Chaire de Génétique Fondamentale, Hôpital des Enfants Malades, Paris, France.
Abstract:
The relative concentrations of plasmatic and urinary amino acids were analysed in 79 trisomic-21 patients, 322 mentally retarded non-trisomic patients, and 206 controls. No true amino acidopathy was found in 21-trisomy, but in plasma a deficit of serine and an excess of cysteine and lysine are highly significant. Excesses of cysteine, methionine, tyrosine, and methyl-histidine are also typical in urine. The increased activity of superoxide-dismutase, cystathionine-beta-synthase, and purine synthesis enzymes, together with the sensitivity to methotrexate, atropine, and dysthyroidism, are in accordance with this shift of equilibrium. A nutritional compensation seems worth investigating.
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