Amylo-1,6-glucosidase activity in leucocytes from patients with glycogen storage disease

The Activity of the Debranching-Enzyme System in Leucocytes

“…The discrepancy between our results and those of W illiams, Kcndig and Field (1963) and Steinitz, Bodur and Arman (1963) may well be caused by the different techniques used for the determ ination of the enzyme activity. These two groups use the reverse reaction of the amylo-l,6-glucosidase reaction (Lanier and Schlisclfeld, 1956) and measure the incorporation of radioactive glucose in glycogen (for experimental details see also Hers, 1964), whereas we measure the glucose production from phosphorylase limit dextrin.…”

“…1). The two enzyme activities have so far not been separated.It has been shown by several investigators th at in patients with glycogen-storage disease type III the debranching enzyme is not only absent or inactive in liver and skeletal muscle hut also in leucocytes ( Williams, Kendig and Field, 1963;Steinitz, Bodur and Arman, 1963: Huijing, 1964) and in erythrocytes (van lloof and Hers, 1966).Enzyme determ inations in these blood cells m ay therefore be used for diagnostic purposes. Moreover two groups obtained indications that this technique might also be useful to screen relatives of patients in order to find heterozygotes.…”

“…Moreover two groups obtained indications that this technique might also be useful to screen relatives of patients in order to find heterozygotes. Steinitz, Bodur and Arman (1963) showed a slightly below normal activity of the debranching-enzyme system in the parents of one patient. Williams, Kendig and Field (1963) found that the debranching-enzyme activity in the parents and a sibling of their patient was approximately half the lowest normal value.…”

Carbohydrate Metabolism by Leukocytes

“…In the following types of glycogenosis the leukocytes show decreased activity of the specific enzyme which characterizes the disease as a particular inborn error of metabolism: (a) glycogenosis type II, glucoamylase (EC 3.2.1.3) [40,41]; (b) glycogenosis type III, dextrin-1.6-glucosidase (EC 3.2.1.33) [41][42][43][44] ; (c) glycogenosis type IV, amylo-(1.4-*-1.6) transglycosylase (a-glucan-branching, glycosyltransferase, EC 2.4.1.18) deficiency [45], and (d) glycogenosis type VI, hepatic phosphorylase (EC 2.4.1.1) deficiency [38,41,43,46,47].…”

Amylo-1,6-Glucosidase Activity and Glycogen Content of the Erythrocytes of Normal Subjects, Patients with Glycogen Storage Disease and Heterozygotes

“…I n order, however, to avoid the discomfort and the potential hazard of biopsies, several authors have developed methods which allow to measure phosphorylase [13,14], amylo-l,6-glucosidase [15,16] and acid maltase [17,18] in circulating leucocytes. The isolation of these cells is best performed on fresh blood samples and we have found it difficult to realize this on blood samples obtained from patients who are geographically removed, as is usual for most cases studied in this laboratory.…”