Some mutations of hemoglobin result in an unstable molecule that easily precipitates, resulting in a Heinz body-positive hemolytic anemia.
Features:
(1) hemolytic anemia, possibly familial
(2) red blood cells containing Heinz bodies
(3) presence of an unstable hemoglobin
(4) exclusion of other causes of Heinz bodies (G6PD deficiency, drugs, oxidating agents, severe alcoholic liver disease)
Unstable hemoglobins include:
(1) Hemoglobin Hammersmith
(2) Hemoglobin Koln
(3) Hemoglobin Olmsted
(4) Hemoglobin Perth
A patient with an unstable hemoglobin may have low pulse oximetry readings.
