Table 1.

Chromosome 16 contains two identical coding sequences for hemoglobin alpha, hemoglobin alpha 2 and hemoglobin alpha 1 (shown here in reference to the zetaglobin gene, which is also located on chromosome 16). Deletions/non-functional mutations are depicted by the absence of a corresponding box. Genotype, red blood cell (RBC) indices, vascular phenotype with relation to blood pressure, and medical classification of the various alpha thalassemia’s are also listed^8,10,44,74.

Alpha Thalassemias
Chromosome 16 (both copies shown)			Genotype	RBC Indices	Vascular Phenotype	Classification
HBZ	m	HBA-1
========|z|===========|α|=======|α|======			αα/αα	Normal	Normal	Normal
========|z|===========|α|=======|α|======
========|z|===========|α|===============			α-/αα	Normal	Moderate hypotension with potential compensation	Alpha thalassemia minima, also known as heterozygo sity for alpha (+) thalassemia, silent carrier of alpha thalassemia, and alpha thalassemia-2 trait
========|z|===========|α|=======|α|======
========|z|===========|α|===============			α-/α- or --/αα	Minimal anemia, decreased MCV and MCH	Moderate hypotension	Alpha thalassemia minor, also known as alpha thalassemia-1 trait (Due to homozygosity for alpha (+) thalassemia (α-/α-) or heterozygo sity for alpha (0) thalassemia (--/αα))
========|z|===========|α|===============
or
========|z|============================
========|z|===========|α|=======|α|======
========|z|===========|α|===============			α-/--	Hemolytic anemia with the formation of P-chain tetramers	None documented	Hemoglobin H (HbH) disease
========|z|============================
========|z|=============================			-/--	Severe anemia due to formation of gamma-4 tetramers (hemoglobin Bart’s)	Hydrops fetalis with increased cerebral blood flow	Hydrops fetalis syndrome with hemoglobin Bart’s
========|z|============================