Glucose-6-phosphate dehydrogenase

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most frequent enzymopathy in human beings. It is prevalent in several ethnical groups (Africans, Asians and Mediterraneans) where it confers protection against malaria. G6PD is crucial in the production of NADPH, which is needed to avoid oxidative stress in cells. The deficiency is caused by an X-chromosome linked mutation. Hemizygous man and homozygous woman have a reduced enzyme activity; whereas heterozygous woman have a variable enzyme expression depending on which of both X-chromosomes is active (lyonization). Most deficient individuals are asymptomatic, although some patients present neonatal jaundice (yellow skin) and acute haemolytic anaemia following an infection or ingestion of oxidative drugs (including some anti-malarial drugs) or fava beans (favism). A list of oxidative drugs should be delivered to the affected patient.