A CHEMICAL INVESTIGATION OF THE DEFECTS OF MYELINATION IN PHENYLKETONURIA

Abstract
The white matter of the brains of four phenyl-ketonurics and five controls has been analysed chemically. The water content in all four phenylketonurics was high compared with that of the controls. The cerebroside content of the dry matter was markedly lower in the phenylketonurics than in the controls, and in cholesterol content was also lower. This is in agreement with the view that the laying down of myelin appears to be hindered in phenylketonuria, but a gradual demyelination is not excluded. This is discussed in relation to the clinical and biochemical features of phenylketonuria. In the oldest case in the present series there were, in the white matter, regions of active demyelination where the water content was still higher, and the cerebroside and free cholesterol content somewhat lower, than in adjoining regions; in these regions of activity demyelination there was an accumulation of cholesterol ester.