G6PD deficiency

What it is

G6PD deficiency shows itself when the red cell meets an oxidant. Hemoglobin is denatured and precipitated inside the cell, and what is left of the cell is read on the blood film.

It is inherited X-linked recessive, beside hemophilia, color blindness, Duchenne muscular dystrophy, Menkes kinky hair disease and adrenoleukodystrophy, and the risk is 50% for a male child in each pregnancy.

Causes and risk

The precipitating factors for hemolysis in G6PD deficiency are infections, bacterial and viral; fava beans; henna; antibiotics such as cotrimoxazole and nitrofurantoin; antimalarial such as primaquine; and NSAID, with a question mark on it. G6PD deficiency is one of the haemolytic causes of neonatal jaundice, and it appears in all three time bands: with jaundice starting at under 24h of age, alongside Rhesus incompatibility, ABO incompatibility, spherocytosis, pyruvate kinase deficiency and congenital infection; with jaundice at 24h to 2 weeks of age, alongside ABO incompatibility; and with jaundice at more than 2 weeks of age, as a haemolytic anaemia.

Primaquine is the one named twice over. In P. vivax and ovale malaria the regimen is chloroquine followed by primaquine for 14 days to destroy the liver phase and prevent relapse, and G6PD is checked before giving primaquine because it can cause hemolysis. In non falciparum malaria the same rule is written as a chloroquine based regimen plus primaquine, after testing for G6PD deficiency, to kill the hypnozoite stage, with primaquine 15 mg, that is 2 tabs, OD for 14 days.