Red Cells Containing Unstable Hemoglobin Variants

In some hemoglobins variants substitution has altered the ability of the hemoglobin to remain in solution in the red cell. The precipitate material is detectable by supravital stain as dark aggregates called Heinz bodies. These intracellular inclusions reduce the life expectancy of the red cell and generate a hemolytic syndrome of varied severity called the congenital Heinz body hemolytic syndrome. Although the formation of methemoglobin might not be the only pathway by which hemoglobin denatures, it is certainly the most common, with the process actually beginning at the level of the iron or at the level of the globin. Heinz bodies, the hallmark of the congenital Heinz body hemolytic syndrome that we are discussing, are the product of hemoglobin denaturation. Hemoglobin is a tight globular protein, which means that the secondary structural arrangements characterizing each subunit must be packed into a solid sphere.