Glutamate dehydrogenase

Glucose-6-phosphate dehydrogenase (G6PD) is an enzyme that plays a crucial role in the pentose phosphate pathway, a metabolic pathway that supplies reducing energy to cells by maintaining the level of the co-enzyme nicotinamide adenine dinucleotide phosphate (NADPH). The NADPH in turn maintains the supply of reduced glutathione in the cells that are used to neutralize oxidative stress.

G6PD is widely distributed in many organisms, including animals, plants, and bacteria. In humans, it is found in all cells, with the highest concentration in the red blood cells. The G6PD gene is located on the X chromosome, which means that this enzyme deficiency is sex-linked.

Function

The primary function of G6PD is to generate NADPH, a crucial co-enzyme in the body's defense against oxidative stress. NADPH helps maintain the supply of reduced glutathione in the cells, which neutralizes the harmful effects of oxidative stress. In red blood cells, where the concentration of G6PD is highest, the enzyme plays a vital role in protecting the cell from oxidative damage.

Clinical significance

Deficiency in G6PD is the most common human enzyme defect, affecting more than 400 million people worldwide. The condition is more prevalent in males than females due to the location of the G6PD gene on the X chromosome.

G6PD deficiency can lead to a range of clinical conditions, including hemolytic anemia, neonatal jaundice, and a severe form of anemia known as favism, which is triggered by the ingestion of fava beans.

Diagnosis and treatment

Diagnosis of G6PD deficiency is typically made through a blood test that measures the level of G6PD enzyme activity. Treatment usually involves avoiding triggers of oxidative stress, such as certain medications, foods, and infections.

See also

• Pentose phosphate pathway
• NADPH
• Hemolytic anemia
• Favism