Contents

Disclaimer

Oxford University Press makes no representation, express or implied, that the drug dosages in this book are correct. Readers must therefore always check the product information and clinical procedures with the most up to date published product information and data sheets provided by the manufacturers and the most recent codes of conduct and safety regulations. The authors and the publishers do not accept responsibility or legal liability for any errors in the text or for the misuse or misapplication of material in this work. Except where otherwise stated, drug dosages and recommendations are for the non-pregnant adult who is not breastfeeding.

Show Summary Details
Page of

Erythrocyte enzymopathies 

Erythrocyte enzymopathies
Chapter:
Erythrocyte enzymopathies
Author(s):

Alberto Zanella

, and Paola Bianchi

DOI:
10.1093/med/9780198746690.003.0540
Page of

PRINTED FROM OXFORD MEDICINE ONLINE (www.oxfordmedicine.com). © Oxford University Press, 2021. All Rights Reserved. Under the terms of the licence agreement, an individual user may print out a PDF of a single chapter of a title in Oxford Medicine Online for personal use (for details see Privacy Policy and Legal Notice).

date: 02 March 2021

Numerous enzymes, including those of the hexose monophosphate and glycolytic pathways, are active in the red cell. They are required for the generation of ATP and the reductants NADH and NADPH. 2,3-Diphosphoglycerate, an intermediate of glucose metabolism, is a key regulator of the affinity of haemoglobin for oxygen, and accessory enzymes are also active for the synthesis of glutathione, disposal of oxygen free radicals, and for nucleotide metabolism. With the exception of heavy metal poisoning and rare cases of myelodysplasia, most red cell enzyme deficiency disorders are inherited. They may cause haematological abnormalities, (most commonly nonspherocytic haemolytic anaemias, but also rarely polycythaemia or methaemoglobinaemia, manifest with autosomal recessive or sex-linked inheritance), and may also be associated with nonhaematological disease when the defective enzyme is expressed throughout the body. Some may mirror important metabolic disorders, without producing haematological problems, making them of diagnostic value. Others are of no known clinical consequence. With rare exceptions, it is impossible to differentiate the enzymatic defects from one another by clinical or routine laboratory methods. Diagnosis depends on the combination of (1) accurate ascertainment of the family history; (2) morphological observations—these can determine whether haemolysis is present, rule out some causes of haemolysis (e.g. hereditary spherocytosis and other red blood cell membrane disorders), and diagnose pyrimidine 5′-nucleotidase deficiency (prominent red cell stippling); (3) estimation of red cell enzyme activity; and (4) molecular analysis. The most common red cell enzyme defects are glucose-6-phosphate dehydrogenase deficiency, pyruvate kinase deficiency, glucose-6-phosphate isomerase deficiency, pyrimidine 5′-nucleotidase deficiency—which may also induced by exposure to environmental lead—and triosephosphate isomerase deficiency.

Access to the complete content on Oxford Medicine Online requires a subscription or purchase. Public users are able to search the site and view the abstracts for each book and chapter without a subscription.

Please subscribe or login to access full text content.

If you have purchased a print title that contains an access token, please see the token for information about how to register your code.

For questions on access or troubleshooting, please check our FAQs, and if you can't find the answer there, please contact us.