Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a hereditary disorder in which red blood cells break down prematurely. G6PD deficiency is caused by deficiency of the enzyme glucose-6-phosphate dehydrogenase. The most common complication of G6PD deficiency is hemolytic anemia, a situation where blood cells are destroyed faster than the body can replace them. Hemolytic anemia is usually triggered by illness and certain medications or foods. During these episodes affected individuals may feel fatigued, experience back pain, shortness of breath, a rapid heart rate and develop jaundice. These symptoms generally resolve within a few weeks. Although G6PD can cause severe jaundice in newborns, many affected individuals remain symptom-free their whole life. There is no cure for G6PD deficiency, however by avoiding or careful surveillance of situations that trigger hemolytic anemia, affected individuals can lead a healthy and active life. G6PD deficiency is caused by pathogenic variants in the G6PD gene.