208 R. G. WESTALL 
ber of further cases has supported this belief. In these cases there is a constant amino- 
aciduria, an intermittent pellagra-like rash, occasional attacks of cerebellar ataxia 
and some degree of mental deficiency. The gross aminoaciduria is thought to be 
mainly, if not entirely, of renal origin as the plasma amino acid levels are not raised 
and in fact seem to be, in respect of serine, threonine and glutamine, lower than usual®®. 
The urinary excretion, shown in Fig. 8, is somewhat similar to that seen in the Fan- 
coni syndrome (Fig. 7), but apart from differences in the concentration of several 

Tk 
ALA ay 
CYS-A 
Chu-nw, 

Fig. 9. A paper chromatogram of the urine from a patient with cystinuria. 
of the amino acids proline is always absent and asparagine is more prominent in the 
Hartnup pattern. Another outstanding biochemical abnormality in this disease is 
the increased excretion of the indole derivatives indolylacetic acid and indolyl- 
glutamine** which are considered to be derived from tryptophane. No single hypo- 
thesis has yet been put forward which could account for the various biochemical 
abnormalities found in these cases. It has been suggested®® that the primary cause 
might bea block in tryptophane metabolism and that the aminoaciduria is a secondary 
effect. On the other hand the primary cause might be an error in the amino acid 
References p. 217/219 
