Final answer:
Heinz bodies, indicating oxidative damage to hemoglobin, are typically seen on a blood smear of a person with G6PD deficiency. G6PD deficiency is a genetic disorder causing hemolytic anemia and is more common in males due to its X-linked inheritance pattern.
Step-by-step explanation:
On a blood smear of a patient with G6PD deficiency, Heinz bodies can be observed within red blood cells using specialized staining techniques like the Wrights-Giemsa stain. These are indicators of the oxidative damage to hemoglobin caused by the lack of G6PD enzyme activity, which is essential for protecting red blood cells from oxidative stress. The direct answer to what is present on a blood smear in active G6PD is Heinz bodies.
In individuals with G6PD deficiency, the blood smear may also indicate signs of hemolytic anemia, especially during oxidative stress caused by infections, certain foods, or medications. The deficiency itself stems from a genetic mutation affecting the enzyme glucose-6-phosphate dehydrogenase, which plays a key role in the pentose phosphate pathway, necessary for the reduction of glutathione to protect red blood cells from oxidative damage.