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Done by : Bara Shayib Supervised by : Dr. Abdullateef Alkhateeb.

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Presentation on theme: "Done by : Bara Shayib Supervised by : Dr. Abdullateef Alkhateeb."— Presentation transcript:

1 Done by : Bara Shayib Supervised by : Dr. Abdullateef Alkhateeb

2 Stands for Glucose 6 phosphate dehydrogenase x- linked disease – autosomal recessive Gene Map Locus: Xq28 Most individuals with G6PD deficiency have a qualitative abnormality in the structure of the G6PD enzyme

3 glucose-6-Phosphate Dehydrogenase(G6PD) deficiency is the most common human enzyme deficiency; an estimated 400 million people worldwide are affected by this enzymopathy a metabolic enzyme involved in the pentose phosphate pathway, especially important in red blood cell metabolism

4 Individuals with the disease may exhibit nonimmune hemolytic anemia in response to a number of causes, most commonly infection or exposure to certain medications or chemicals G6PD deficiency is closely linked to favism, a disorder characterized by a hemolytic reaction to consumption of broad beans

5 G6PDH is the most common human enzyme defect, being present in more than 400 million people worldwide. African, Middle Eastern and South Asian people are affected the most

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7 Hemolytic anemia Neonate jaundice Infections

8 Oxidation of the sulfhydryl groups on hemoglobin leads to the formation of methemoglobin and then denatured globin or sulfhemoglobin, which form insoluble masses that attach to the red cell membrane (called Heinz bodies) The net effect is that the deficient red cells become rigid and nondeformable, making them susceptible to destruction by reticuloendothelial macrophages in the marrow, spleen and liver Although this type of hemolysis is predominantly extravascular, intravascular hemolysis also occurs, leading to hemoglobinemia and hemoglobinuria

9 The clinical picture of neonatal jaundice in this setting differs from classic neonatal jaundice in two main respects : First, G6PD deficiency related neonatal jaundice is rarely present at birth; the peak incidence of clinical onset is between days two and three Second, there is more jaundice than anemia, and the anemia is rarely severe

10 The pathogenesis of this type of neonatal jaundice remains uncertain. Some believe that decreased hepatic bilirubin elimination is a key factor while others maintain that increased hemolysis causes the hyperbilirubinemia We afraid from kernicterus

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13 (Type 1 ) Severe deficiency (<10% activity) with chronic (nonspherocytic) hemolytic anemia (Type 2) Severe deficiency (<10% activity), with intermittent hemolysis (Type3) Mild deficiency (10-60% activity), hemolysis with stressors only (Type 4) Non-deficient variant, no clinical sequelae (Type5) Increased enzyme activity, no clinical sequelae

14 The diagnosis is generally suspected when patients from certain ethnic groups develop anemia, jaundice and symptoms of hemolysis Positive family history

15 Complete blood count and reticulocyte count; in active G6PD, Heinz bodies can be seen in red blood cells on a blood film Liver enzymes (to exclude other causes of jaundice) Lactate dehydrogenase (elevated in hemolysis and a marker of hemolytic severity) A "direct antiglobulin test" (Coombs' test) – this should be negative, as hemolysis in G6PD is not immune-mediated

16 The Beutler fluorescent spot test direct DNA testing and/or sequencing of the G6PD gene

17 The most important measure is prevention-- -- avoidance of the drugs and foods that cause hemolysis Vaccination against some common pathogens n the acute phase of hemolysis, blood transfusions might be necessary

18 dialysis in acute renal failure removal of the spleen (splenectomy) Although vitamin E and selenium have antioxidant properties

19 Leukocyte and platelet G6PD is regulated by the same gene as that in red cells; as a result, deficient individuals have reduced enzyme activity in these cells, particularly patients with more severe enzyme deficiency such as G6PD Mediterranean However, this abnormality is rarely associated with functional impairment of leukocytes and platelets due to their normally short survival. As an example, phagocytic and bactericidal activity of granulocytes are typically normal in deficient subjects

20 G6PD-deficient individuals do not appear to acquire any illnesses more frequently than other people, and may have less risk than other people for acquiring (ischemic heart disease)and cerebrovascular disease Possible protection against malaria

21 THANK YOU


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