|
Red Blood Cell Enzyme Disorders:
INHERITANCE PATTERN:
Most are autosomal recessive
Two are X-linked (G6PD, PGK)
One is autosomal dominant
CLINCAL FEATURES:
Life-long hemolysis
Episodic hemolysis ie when exposed to certain drugs
BlOOD SMEAR:
Usually normal except for macrosytosis or spiculated RBCs.
Basophilic stippling: seen in PYRIMIDINE 5' NUCLEOTIDE deficiency
If you see elliptocytes, spherocytes, acanthocytes, or schistocytes, it is most likely not an enzyme disoder.
LABORATORY FINIDINGS:
Cooms negative
Increased osmotic fragility
Increased I. Bili
Decreased haptoglobin
Increased LDH
LIST OF ENZYMES:
1. G6PD (most common)
2. Pyruvate Kinase (most common)
3. GPI deficiency
4. Hexokinase
5. PGK deficiency (X-linked)
6. PFK deficiency
7. TPI deficiency
8. Hyperactivity of ADA (adenine deaminase)
|
