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Pathology -Glucose-6-phosphate dehydrogenase deficiency
Definition: An hereditary hemolytic disorder resulting from a mutation in the glucose-6-phosphate dehydrogenase (G6PD) gene.
Epidemiology • Prevalent, impacting up to 10% of the global population. • There is significant geographical heterogeneity, with the highest rates observed among Africans, Asians, Italians, and Greeks. The G6PD gene is on the X chromosome. • A solitary mutant allele, consequently, induces G6PD deficiency in males.
Homozygous women are similarly impacted, although such people are rarely observed. Heterozygous women exhibit no clinical signs, as the normal allele generates sufficient enzyme activity.
Pathogenesis • G6PD is an enzyme involved in the hexose monophosphate pathway, a metabolic process essential for the production of reduced glutathione. • Reduced glutathione safeguards the red blood cell membrane from oxidative damage. • Individuals with G6PD deficiency experience episodes of hemolysis in response to oxidative stress.
Presentation • The majority of individuals remain asymptomatic with normal hemoglobin levels. • Upon exposure to oxidants, they may experience an acute hemolytic episode characterized by fever, jaundice, and dark urine resulting from hemoglobinuria. • Frequent precipitants include medications (notably anti-malarials) and fava beans, a prevalent food in Mediterranean regions. Complete blood count • decreased hemoglobin during an acute hemolytic event.
Peripheral blood smear • Alteration in erythrocyte morphology (poikilocytosis). • Erythrocytes exhibiting indentations in their peripheries, known as 'bite cells,' are distinctive. Spherocytes may also be observed. Supplementary examinations Screening assays for G6PD deficiency are available that indirectly evaluate G6PD activity by assessing the capacity of red blood cells to decrease dyes. • A definitive diagnosis necessitates direct enzyme assay.
Definition: An hereditary hemolytic disorder resulting from a mutation in the glucose-6-phosphate dehydrogenase (G6PD) gene.
Epidemiology • Prevalent, impacting up to 10% of the global population. • There is significant geographical heterogeneity, with the highest rates observed among Africans, Asians, Italians, and Greeks. The G6PD gene is on the X chromosome. • A solitary mutant allele, consequently, induces G6PD deficiency in males.
Homozygous women are similarly impacted, although such people are rarely observed. Heterozygous women exhibit no clinical signs, as the normal allele generates sufficient enzyme activity.
Pathogenesis • G6PD is an enzyme involved in the hexose monophosphate pathway, a metabolic process essential for the production of reduced glutathione. • Reduced glutathione safeguards the red blood cell membrane from oxidative damage. • Individuals with G6PD deficiency experience episodes of hemolysis in response to oxidative stress.
Presentation • The majority of individuals remain asymptomatic with normal hemoglobin levels. • Upon exposure to oxidants, they may experience an acute hemolytic episode characterized by fever, jaundice, and dark urine resulting from hemoglobinuria. • Frequent precipitants include medications (notably anti-malarials) and fava beans, a prevalent food in Mediterranean regions. Complete blood count • decreased hemoglobin during an acute hemolytic event.
Peripheral blood smear • Alteration in erythrocyte morphology (poikilocytosis). • Erythrocytes exhibiting indentations in their peripheries, known as 'bite cells,' are distinctive. Spherocytes may also be observed. Supplementary examinations Screening assays for G6PD deficiency are available that indirectly evaluate G6PD activity by assessing the capacity of red blood cells to decrease dyes. • A definitive diagnosis necessitates direct enzyme assay.
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