Delta-Beta Thalassaemia in a Pathan Family

Delta-beta-thalassaemia (δβ-thalassaemia) is a rare type of thalassaemia which mostly results from deletion of δ and β genes with preservation of γ genes. δβ-thalassaemia is classified into (δβ)+ and (δβ)0 types. The (δβ)0-thalassemia is further divided into GγAγ(δβ)0-thalassaemia and Gγ(Aγδβ)0-thalassaemia. In heterozygous state, (δβ)0mutations give rise to phenotype resembling β-thalassaemia trait but with raised Hb-F, ranging from 5 to 20%, without a rise in Hb-A2. In homozygotes, the clinical picture is usually that of thalassaemia intermedia and the patients have 100% Hb-F. Workup of a 1-year child suffering from pallor, chronic ill health, and splenomegaly referred to our laboratory with the suspicion of β-thalassaemia, ultimately resulted in a diagnosis on polymerase chain reaction as having homozygous inversion/deletion Gγ(Aγδβ)0-thalassaemia. Her family members were also investigated.