But thalassemia is different: Instead of abnormal hemoglobin, the main problem is a decreased amount of normal globin. (scientificamerican.com)
Sickle cells contain abnormal hemoglobin called sickle hemoglobin or hemoglobin S. (sciencedaily.com)
In 1948 British biochemist and evolutionary biologist J. B. S. Haldane noticed that the distribution of populations with abnormal hemoglobin coincides with the distribution of malaria. (discovermagazine.com)