Protein and RNA Synthesis in Trisomic Down's Syndrome Leucocytes

Abstract

IN Down's syndrome (mongolism) increased activities have been reported in the leucocyte enzymes alkaline^1,2 and acid³ phosphatase, glucose-6-phosphate dehydrogenase (G-6-PD) (ref. 3), galactose-1-phosphate uridyl transferase³ and 5-nucleotidase². It has been suggested that such increases may be due to the siting of structural genes for the relevant enzyme on the trisomic “G” group autosome¹. This seems unlikely, however, at any rate in the case of G-6-PD, for there is good evidence that the structural gene for this enzyme is carried on the X chromosome^3,4. An alternative possibility is that the trisomic autosome may carry genetic material responsible for regulation of protein synthesis.