Thalassemia is best thought of as a group of disorders rather than a single disease. They demonstrate a hemoglobin synthesis disorder in which there exists a defect in the rate of production of one or more of the globin chains. This defect results from either a heterozygous or homozygous deletion or inactivation of a globin chain gene.
Thalassemias are named according to the affected gene or globin chain which is showing reduced or absent synthesis. Globin chain gene loci are found on the following chromosome locations:
- Chromosome 11 (Beta, Delta, Epsilon, and Gamma)
- Chromosome 16 (Alpha, and Zeta)