Coexistence of hemoglobin Handsworth and alpha 3.7 kb deletion in Caucasian woman in Poland
Abstract
Background
This report presents a case of an adult Polish women of Caucasian origin who was heterozygous for the nondeletional mutation: Hb Handsworth (HBA2 or HBA1: c.55G > C, p.Gly19Arg) and deletional (-α) α-thalassemia mutation.
Methods
The HbA and HbF levels were measured by microcolumn chromatography and alkaline denaturation procedure, respectively, while electrophoresis was used to detect pathological hemoglobin fraction. The β- and α-globin genotypes were determined by DNA sequencing, gap-polymerase chain reaction, α gene triplication and MLPA.
Results
The HbA and HbF levels were normal, but hemoglobin electrophoresis on agarose gel alkaline pH showed a strong band migration in a position of hemoglobin S and faint bands in the neighborhood of band A on acid electrophoresis. Molecular analysis of the alpha globin cluster detected a point mutation at codon 19 in (c.55G > C, p.Gl- y19Arg) and deletion -α.
Conclusions
Our compound heterozygosity does not produce severe clinical or hematological symptoms but it is important to say that in our part of Europe such cases do appear. Molecular analysis of the alpha globin cluster is required for correct diagnosis in patients with normal HbA levels. Compound heterozygosity was unmasked by molecular diagnosis only.
Keywords: α-thalassemiaHb HandsworthAlpha 3.7 kb deletion