Being a carrier of the disease may confer a degree of protection against malaria, and is quite common among people from Italian or Greek origin, and also in some African and Indian regions.
This is probably by making the red blood cells ''more'' susceptible to the less lethal species ''Plasmodium vivax'', simultaneously making the host RBC environment unsuitable for the merozoites of the lethal strain ''Plasmodium falciparum''. This is believed to be a selective survival advantage for patients with the various thalassemia traits. In that respect it resembles another genetic disorder, sickle-cell disease.
Epidemiological evidence from Kenya suggests another reason: protection against severe anemia may be the advantage.
People diagnosed with heterozygous (carrier) Beta-Thalassemia have some protection against coronary heart disease.
Further Reading
This article is licensed under the Creative Commons Attribution-ShareAlike License.
It uses material from the Wikipedia article on
"Thalassemia"
All material adapted used from Wikipedia is available under the terms of the
Creative Commons Attribution-ShareAlike License.
Wikipedia® itself is a registered trademark of the Wikimedia Foundation, Inc.