The authors examined the soluble proteins of the brain frontal lobes in the 
newborn with trisomias of the 13th, 18th, and 21st chromosomes (Down's, Patau's, 
and Edwards' syndromes). The examinations were carried out on autopsy material 
(the post-mortem period not exceeding 24 hours) by the method of disc 
electrophoresis in polyacrylamide gel. The brain tissue was taken from 17 
newborn infants with Down's syndrome; 9 infants with Patau's syndrome; and 7 
infants with Edwards' syndrome. For the control the brain of 21 newborn infants 
without defects of the CNS development (the death cause being analogous) was 
taken. In all the syndromes studied diversely directed but relatively specific 
shifts were revealed on the proteinograms. It was the albumin section which 
appeared to be the most sensitive to the chromosomal pathology: in cases of 
Down's and Patau's syndromes the protein content in it was reduced, whereas in 
cases of Edwards' syndrome it was increased. In the latter syndrome the relative 
amount of neuronines S-5 and S-6, and in Patau's syndrome the amount of 
neuronine S-6 were lowered, this lowering being statistically significantly. In 
all the trisomias a tendency to a diminution of the zone of the acidic 
neurospecific cerebral proteins was noted. This is, possibly, due to the lower 
level of the CNS functional activity in chromosomal pathologies.