BODY FLUIDS AND EFFECT OF HEREDITARY DISORDERS PATA 
after a few days on a milk diet begin to vomit and fail to thrive. If the milk diet is 
continued other clinical features such as abdominal distension, hepatomegaly and 
possibly jaundice may show. There is also a gross-generalized aminoaciduria, shown 
in Fig. 10, and an excessive excretion of galactose in the urine. These children are 
unable to metabolize galactose, which is derived from the lactose in the milk, in the 
normal way. Enzyme studies on the red blood cells and on liver biopsy samples from 
affected patients have established that they lack an enzyme necessary for the con- 
version of galactose to glucose 1-phosphate®’. This enzyme has since been tracked 
down to galactose 1-phosphate uridyl transferase®*. Fortunately, if the source of 
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Fig. 12. A paper chromatogram of the blood plasma from the phenylketonuric patient. 
galactose 1s removed from the diet then the infants recover but, however, if the ex- 
posure to galactose has been prolonged some of the damage is irreversible. With the 
removal of galactose from the diet the aminoaciduria clears up but reappears on 
restoring the galactose. It is therefore considered, in this disease, that the amino- 
aciduria is of a secondary nature only and may be due to some toxic effect on the kidney 
tubule caused either by galactose itself or by one of its metabolites. 
References p. 217/219 
