Enzymes in Plasma and Cerebrospinal Fluid

Alterations in the activities of various serum enzymes in TSD have been discovered during the last few years (Aronson et al. 1961). 

SGOT levels were consistently elevated in 30 patients with TSD, with values up to five times normal. A slow decline of the enzyme activity after the first 20 to 24 months towards a normal level occurred concomitantly with the beginning of the protracted stage of the disease. SGOT-elevation appears to precede neurologic signs and may be indicative of the disease in children who are still asymptomatic. There is a similar time course of GOT activity in the cerebrospinal fluid. 

Lactic acid dehydrogenase and malic acid dehydrogenase are also increased with a maximum for both enzymes after two years and a decrease thereafter. 

Of great interest is the discovery of a deficiency or absence of fructose-1-phosphate aldolase in TSD serum (Volk et al. 1964). The enzyme, which normally catalyzes the splitting of fructose-1-phosphate into two three-carbon compounds which then gain access to the glycolytic pathway, was determined by a modi- 

In contrast to hereditary fructose intolerance where lack of fructose-1-phosphate aldolase (Levin et al. 1963) in serum and liver is a prominent feature, liver fructose-1-phosphate aldolase activity in TSD is only reduced to approximately 60%, and fructose tolerance is not impaired in the latter disorder (Schneck et al. 1965), while in the former accumulation of fructose-1-phosphate and hypoglycemia 

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