Glucose-6-phosphate Dehydrogenase Deficiency: Biochemical and Histochemical Studies on Hair Roots for Carrier Detection

Abstract

Kinetic properties of human hair root glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase were studied in order to optimize the assay of these enzymes in lysates from single hair roots. In contrast to previously reported methods, an excess of purified 6-phosphogluconate dehydrogenase was added to the glucose-6-phosphate dehydrogenase reaction mixtures, thus allowing a more exact quantification of glucose-6-phosphate dehydrogenase activity. Although enzyme histochemical techniques suggest a similar distribution of hair root glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase, enzyme assays on hair root segments after microdissection nevertheless indicate differences in the distribution of these enzymes. Upon storage a gradual drop in the activity of both hair root enzymes was found, but the rate of decrease in enzyme activity was about equal: the enzyme activity ratio was, therefore, not affected. This opens interesting possibilities for mailing hair roots for screening purposes without any special precautions.Glucose-6-phosphatdehydrogenase-Mangel: Biochemische und histologische Untersuchungen an Haarwurzeln zum Überträger-Nachweis

Heterozygote detection in glucose‐6‐phosphate dehydrogenase deficiency: limitation of hair follicle analysis

“…The apparent Km's for glucose-6phosphate and NADP were 2 mM and 1 mM, respectively. These data are in agreement with the findings for normal hair root glucose-6-phosphate dehydrogenase (Vermorken et al 1979).…”

“…The parents of these patients were not available for study. Hair root lysates were prepared and assayed for the activities of glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase according to procedures described elsewhere (Vermorken et al 1979).…”

“…Methods using hair roots have been described for the detection of females heterozygous for X-linked inherited enzyme defects, such as deficiency of hypoxanthineguanine phosphoribosyl transferase (Gartler et al 1971, Francke et al 1973, de Bruyn et al 1974), a-galactosidase (Grimm et al 1976, Beaudet & Caskey 1978, Vermorken et al 1978) and glucose-6-phosphate dehydrogenase (Romeo et al 1976, Vermorken et al 1979). These methods seem to give reliable results.…”

Phosphoglycerate Kinase Deficiency: Biochemical Studies on Hair Follicles

“…Since most human hair follicles are of clonal origin, the hair follicle will in this respect behave s cell clones (7). Hair follicles have already been shown to be convenient tissue specimens for detection of several other X-linked enzyme deficiencies (8,9,10).…”

“…The glucose-6-phosphate dehydrogenase assay and the 6-phosphogluconate dehydrogenase assay were essentially the same s described earlier (10). In the glucose-6-phosphate dehydrogenase assay 15 μΐ hair follicle lysate was added to 130 μΐ incubation mixture containing 0.1 raol/1 2-amino-2-methyl-l ,3-propanediol (pH 8.6), 20 mmol/1 glucose-6-phosphate, 2.5 mmol/1 magnesium chloride, 10 mmol/1 NADP+, 0.5 mmol/1 EDTA, 0.5 g/l bovine serum albumin and 300 milli-units 6-phosphogluconate dehydrogenase.…”