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15 Cards in this Set
- Front
- Back
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What is the rate limiting step in heme synthesis?
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Succinyl CoA + glycine to delta-ALA via ALA synthase with coenzyme pyridoxal phosphate
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What is sideroblastic anemia? Tx?
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Mutation in ALAS2 gene on X coding for ALA synthase. Low heme, abnormal erythroblasts. Tx wit pyridoxine.
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What Rx can tx prophyria and how?
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Hematin or heme aginate can allosterically inhibit ALA synthase thus decreasing heme synthesis.
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What toxin can interfere with the synthesis of heme and how?
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Lead can inhibit ALA dehydratase and ferrochetalase leading to anemia.
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What enzyme is involved in introducing Fe to protoporphrin IX? What pathology is assoc. with it?
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Ferrochetalase. Erythropoetic protoporphyria (autosomal recessive).
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What is the affected enzyme, accumulated product and symptoms in X linked dominant protoporphyria?
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ALA synthase. Free and Zn protoporphyrin IX. Photosensitivity and liver damage.
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What is the affected enzyme, accumulated product and symptoms in acute intermittent prophyria?
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Hydroxymethlbilane synthase. Prophobilinogen and delta ALA. Abd pain, N/V. (Liver)
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What is the affected enzyme, accumulated product and symptoms in Porphyria cutanea tarda?
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Uroporphyrogen decarboxylase. Uroporphyrin in urine. Photosensitivity. (Liver and bone marrow)
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What is the affected enzyme, accumulated product and symptoms in hereditary corpoporphyria?
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Corporphyrinogen oxidase. Corpoporphyrinogen III. Photosensitivity, N/V. (Liver)
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What is the affected enzyme, accumulated product and symptoms in erythropoetic protoporphyria?
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Ferrochelatase. Protoporphyrin in RBCs, marrow and plasma. Photosensitivity.
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What is the affected enzyme, accumulated product and symptoms varigate porphyria?
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Protoporphyrinogen oxidase. Protoporphyrin IX. Photosensitive (liver).
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What is the affected enzyme and accumulated product in Gilbert's syndrome?
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25-30% reduction in glucuronyl transferase. Unconj. bili. Pt may be asymptomatic.
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What is the affected enzyme, accumulated product and symptoms in Cringer-Najjar syndrome?
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Present with severe unconj. hyperbili d/t def. in glucuronyl transferase. Can cause kernicterus in neonates.
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What is the affected enzyme, accumulated product and symptoms in Dublin-Johnson syndrome?
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Impaired biliary secretion of conj. bili. Black pigmentation of liver. Mutation in organic anion transporter.
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What is the affected enzyme, accumulated product and symptoms in Rotor syndrome?
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Impaired biliary secretion of conj. bili. NO Black pigmentation of liver! Exact enzyme unknown.
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