Anaemia - Glucose-6-Phosphate Deficiency (Normocytic)

Question 1

Definition

Answer 1

X linked condition where people are deficient in G6PD = enzymopathy causing 1/2 lifespan + RBC degradation
G6PDH = protective against oxidative damage
G6PD is located on chromosome Xq28 near factor III gene

Question 2

Epidemiology

Answer 2

Male
Ethnic origin -
- Black
- Mediterranean
- Asia
Family history

Question 3

Pathophysiology

Answer 3

G6PD is necessary for RBCs by providing NADPH which is used with glutathione to protect the RBC from OXIDATIVE DAMAGE from compound such as hydrogen peroxide

Question 4

How are oxidative crises induced

Answer 4

Recent exposure to oxidative drugs
- Anti-malarial = PRIMAQUINE
- Painkillers = ASPIRIN, IBUPROFEN
- Sulphonamide containing drugs = TRIMETHROPRIM
Infections
Ingestion of fava beans = favism
Naphthalene = in moth balls - major cause

Question 5

Signs and symptoms

Answer 5

Most are asymptomatic until exposed to oxidative stress:
Jaundice - Hb break down into bilirubin
Dark red urine - Increased Urobilin
Back pain - due to kidney damage from increased urobilin
Anaemic symptoms
- Fatigue
- Pallor
- Tachycardia
Gallstones
Spleneomegaly

Question 6

Diagnosis

Answer 6

FIRST LINE = Normal in-between attacks - ATTACKS = Decreased RBC, Increased Reticulocytes
Normocytic Normochromic RBC
Heinz bodies + Bite cells (BEANS MEANS HEINZ)
GOLD STANDARD = Enzyme assay/spectrophotometric assay = detects levels of G6PD enzyme - LOW

Question 7

Treatment

Answer 7

AVOID PRECIPITANTS
Blood transfusions when attacks ensue