C. METABOLIC DISORDERS Flashcards
pathway to achieve the end result of certain classes
Metabolic disorders
- inherited sex-linked
- complex heterogenous disorder which is ubiquitous
- seen in enzyme deficient HA
G6PD DEF
seen in blast
Type A G6PD def
px are susceptible to severe oxidant hemolysis so more severe; seen among Mediterranean
race
Type B G6PD def
most delicate; life-threatening hemolysis
occurs a few hrs after eating fava beans
Favism
G6PD DEF LAB TESTS
o Methyl Violet or Crystal Violet
o Dye Reduction test
o Ascorbate Cyanide test
o Fluorescent Spot test
o Quantitative Assay of G6PD
- Causes an abnormality in anaerobic glycolysis that
causes a moderately severe anemia. - Lab findings:
o ↑retic ct. - PBS:
o Anisocytosis & poikilocytosis
GLUCOSE PHOSPHATE ISOMERASE DEF
- most common red cell enzyme deficiency involving
the Embden-Meyerhof Glycolytic pathway - Inherited disorder
- PK converted to phosphophenolpyruvate to pyruvate
in the EMP w/ the production of ATP - RBC loses its flexibility due to ↓ATP
- Mild to moderately HA w/ splenomegaly
PYRUVATE KINASE DEF
PYRUVATE KINASE DEF PBS:
o No notable red cell abnormalities until after
splenomegaly
o Ecchinocytes
o Irregularly contracted red cells
o Crenated red cells may be prominent
- Inherited
- Caused by an abnormality in nucleotide metabolism
- Acquired occurs in lead poisoning & responsible for the
basophilic stippling
PYRIMIDINE-5-NUCLEOTIDASE (PN) DEF
- Lab findings:
o Reticulocytosis
o (+) in demonstration of ↓ nucleosidase
activities - PBS:
o Marked basophilic stipplings in red cells
PYRIMIDINE-5-NUCLEOTIDASE (PN) DEF
- Are other enzyme deficiencies that involve anaerobic
glycolysis.
- TRIOSEPHOSPHATE ISOMERASE
- HEXOKINASE
- DIPHOSPHOGLYCERATE MUTASE DEFICIENCIES
- Also show hemolytic anemia – these enzymes are
required in the HMP like G6PD, hemolysis ↑due to
oxidant drug exposure or infection.
GLUTATHIONE SYNTHASE, GLUTATHIONE PEROXIDASE &
GLUTATHIONE REDUCTASE DEFICIENCIES (G S,P,R)
