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Everybody has a series of haemoglobin genes. These are normal so not considered mutant.
Haemoglobin molecules usually consist of four sub-units of haemoglobin. The forms that are produced vary during the lifecycle.
The embryo produces haemoglobins alpha, gamma and epsilon, while the later fetus produces mainly alpha and gamma haemoglobins. This form has a higher affinity for oxygen than adult haemoglobin, allowing the fetal blood to "steal" oxgen from the mother's blood.
Adults usually produce mainly alpha and beta haemoglobins.
The delta form is less common and therefore not very important.
Mutant forms of haemoglobin are those which have different oxygen carrying abilities that are detrimental, for example haemoglobin S, which causes sickle cell anaemia.
Epogen is an artificial form (created using recombinant DNA- inserting the human gene into mammalian cells) of the hormone epoetin alfa, which stimulates production of red blood cells by the bone marrow. It is given to patients undergoing cancer therapy or with kidney failure. Iron supplements are sometimes recommended alongside epogen.
Epogen is sometimes used when blood needs to be harvested, for example for autologous blood transfusion during an operation.
There are safety risks with epogen, and doctors in the US were recently criticised for overusing this type of medicine.
Epogen may also be used illegally in sports, but is dangerous when used in otherwise healthy people. There are reports of deaths, usually when the athlete is lying down and asleep, caused by the thickening of the blood with extra red blood cells.
The presence/absence of something in blood makes me think of the rhesus factor.
