Full-size Left-side Hidden
CHAPTER 45 – RED BLOOD CELL ENZYMOPATHIES

Xylina T. Gregg,
Josef T. Prchal

Clinically significant abnormalities of red blood cell enzymes cause diverse clinical abnormalities, including hemolytic anemia, polycythemia, and methemoglobinemia. Deficiencies of some red cell enzymes may also provide a protective advantage to external challenges. Common mutations of glucose-6-phosphate dehydrogenase (G6PD) likely reached their prevalence by providing some protection against lethal malarial complications. In other instances, although there is no detectable red blood cell phenotypic abnormality, enzymes from easily accessible red blood cells can be assayed to diagnose systemic disorders such as galactosemia, adenosine deaminase deficiency, and deficiencies of some vitamins, for example, riboflavin. In addition, the study of red blood cell enzymes has helped to uncover important biologic principles, such as X-chromosome inactivation, and provided the groundwork for important principles of population …