α-Thalassemia major

Fig: Cellulose acetate electrophoresis at pH 8.6.

1.      F, A, Hb Bart, Albumin in newborn.

2.      A, HbH, Albumin in an adult

3.      HbA and HbJ in adult

α-Thalassemia major: 

(α-Thalassemia major is the result of a two α-chain gene deletion. These deletions may be on same gene (-/αα, α⁰-thalassemia) described as cis-deletion or on different genes (-α/-α, α⁺-thalassemia) described as trans deletion. The CBC shows mildly reduced Hb level with low MCV and MCH. HbF and HbA₂ within reference level. The presence of thalassemic indices in patient with normal HbA₂ and HbF is often the basis for diagnosis of α-thalassemia major, particularly if family history is positive.

Thalassemia trait: 

There is a single α-globin chain deletion (-α/αα). A CBC shows normal or marginally reduced Hb, MCV and MCH.