The Alpha thalassemia genetic defects can be heterozygous or homozygous in inheritance. The heterozygous states of alpha thalassemia express themselves as:
- silent carrier (one of four gene loci deleted)
- thalassemia minor (two of four gene loci deleted)
- hemoglobin H disease (three of four gene loci deleted)
The homozygous state (all four gene loci deleted), alpha thalassemia major, is incompatible with life. This is called alpha thalassemia major or hydrops fetalis.
