A Brief Overview of Thalassemia

HBB Gene Must Hurt by Beta Thalassemia

Beta-Thalassemia

Beta Thalassemia is actually due to mutations in the HBB gene on chromosome 11,also inherited in an autosomal, recessive fashion. The severity of the disease depends on the nature of the mutation. Mutations are characterized as either βo or β Thalassemia major if they prevent any formation of β chains, the most severe form of β-Thalassemia; as either β+ or β Thalassemia intermedia if they allow some β chain formation to occur; or as β Thalassemia minor if only one of the two β globin alleles contains a mutation, so that β chain production is not terribly compromised and patients may be relatively asymptomatic.

Alpha Thalassemia - Severe Genetical Blood Disorder

Alpha-Thalassemia

The α-Thalassemia involves the genes HBA1 and HBA2, inherited in a Mendelian recessive fashion. Two gene loci and so four alleles exist. It is also connected to the deletion of the 16p chromosome. α Thalassemia result in decreased alpha-globin pro

duction, therefore fewer alpha-globin chains are produced, resulting in an excess of β chains in adults and excess γ chains in newborns. The excess β chains form unstable tetramers (called hemoglobin H or HbH of 4 beta chains), which have abnormal oxygen dissociation curves.