Heme synthesis and pathology Flashcards Preview

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Flashcards in Heme synthesis and pathology Deck (13):
1

Mnemonic for hemoglobin development sites

"young Liver Synthesizes Blood"

Yolk sac (week 3-8)
Liver (week 6- birth)
Spleen (Week 10 -28 weeks)
Bone marrow (Week 18- adult; prominent week 28)

2

Composition of embryonic fetal globins

Hb Gower -- 2 zeta 2 epsilon

3

Fetal hemoglobin?

Hb F:
2 alpha 2 delta

4

Adult hemoglobin

Hb A:
2 alpha 2 beta

5

2% of normal hemoglobin is composed of?

Hb A 2 :
2 alpha, 2 delta

6

Hb in poorly controlled diabetes:

Hb A1c:

2 alpha 2 beta--glucose

7

Sickle cell hemoglobin

HbS :

2 alpha 2 beta S ( glu--> val in beta chain)

8

Hemoglobin C disease

Also seen in sickle cell population

HbC:

2 alpha 2 beta (glu --> lysine in beta chain)

9

Type of hemoglobin you see in severe alpha thalassemia

- 3 mutations?
- 4 mutations?

Hb H: ( 3 mutations)
4 beta ( no alpha chains)

Hb Bart's: (4 mutations)
4 gamma ( no alpha chains)
- hydrops fetalis and death

10

Lead poisoning:

Enzyme blocked?

Accumulated substrate?

Presenting symptoms?

tx?

Aminolevulinic acid (ALA) dehydratase
Ferrochelatase

Delta-aminolevulinic acid ( delta- ALA) and
Protoporphyrin

- Microcytic anemia
- Encephalopathy
- Memory loss + delirium + mental deterioration
- Foot drop/ wrist drop
- Microcytic anemia and basophilic stippling + siderblastic anemia (in bone marrow)
- Lead lines in gums and bones (children)
- colicy abdominal pain
- renal failure in adults

EDTA or Succimer for adults and children

If very severe toxicity = Dimercaprol + succimer

11

Acute intermittent prophyria

Enzyme blocked?

Accumulated substrate?

Presenting symptoms?

tx?

Porphobilinogen deaminase ( aka uroporphinogen-1-synthase deficiency)

Porphobilinogen, delta ALA, coporphobilinogen (urine)

5 P's:

Painful abdomen
Port wine colored urine
Polyneuropathy
Psychological disturbances
Precipitaed by drugs (barbituates, seizure drugs, rifampin, and methoclopramide; cytochrome P-450 inducers, alcohol, and starvation

Tx: glucose and heme -- inhibit ALA synthase

12

Porphyria cutanea tarda

Enzyme blocked?

Accumulated substrate?

Presenting symptoms?

Uroporphyrinogen decarboxylase

Uroporphyrin ( tea colored urine)

Symptoms:
- blistering of skin and photosensitivity
- tea colored urine
- Hypertrichosis (facial hair growth)
- Facial hyperpigmentation
- Hep C
- Alcoholism

13

Hemoglobin in beta- thalassemia

(2 genes)

Beta - thalassemia minor
- beta chain is underproduced
- asymptomatic
-diganosis confirmed with an increasei n HbA 2

Beta thalassemia major
- Beta chain is absent --> severe anemia