[Delta⁰-thalassemia by insertion of 27 base pairs in δ-globin gene with decreased hemoglobin A₂ levels].

Abstract

BACKGROUND AND OBJECTIVE:

We describe a novel delta-thalassemia mutation causing decreased hemoglobin (Hb) A2 levels associated with Hb Watts, variant Hb resulting from a trinucleotide deletion in Spain.

PATIENTS AND METHOD:

Hb variant analysis was performed by cation-exchange high performance liquid chromatography (HPLC) and capillary zone electrophoresis. Polymerase chain reaction and DNA sequence analyses were used to identify mutations in the δ- and α-globin genes.

RESULTS:

Abnormal Hb was observed on capillary zone electrophoresis in Z6 and by cation-exchange HPLC a slower peak than HbA was observed at an retention time of 4.19min. This variant Hb is called Hb Watts [α2 74(EF3)Asp->0 or α2 75(EF4)Asp->0; HBA2:c.226_228delGAC]. The decreased HbA2 percentage owes to an insertion of 27nt between nt 83 and 84 of IVS-I of the δ-globin gene.

CONCLUSIONS:

When analyzing a chromatogram, the possibility of the existence of delta-thalassemia or an HbA2 variant should be considered, apart from alfa-, beta-thalassemia and structural haemoglobinopathies. To this end, each of the peaks and their percentages should be considered to allow for correct interpretation and to avoid misdiagnosis as much as possible.

• Authors: Maria Luisa González Borrachero, Félix de la Fuente-Gonzalo, Fernando Ataúlfo González, Jorge M Nieto, Ana Villegas, Paloma Ropero
• Journal: Medicina clinica (Med Clin (Barc)) Vol. 144 Issue 7 Pg. 312-6 (Apr 08 2015) ISSN: 1578-8989 [Electronic] Spain
• Vernacular Title: Delta(0)-talasemia por inserción de 27 pares de bases en el gen δ-globina con descenso de los valores de hemoglobina A2.
• PMID: 25579773 (Publication Type: Case Reports, English Abstract, Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2014 Elsevier España, S.L.U. All rights reserved.

Chemical References

• Biomarkers
• Hemoglobins, Abnormal
• alpha-Globins
• delta-Globins
• hemoglobin Watts
• Hemoglobin A2

Topics

• Base Sequence
• Biomarkers (blood)
• Female
• Hemoglobin A2 (genetics, metabolism)
• Hemoglobins, Abnormal (genetics, metabolism)
• Humans
• Middle Aged
• Mutagenesis, Insertional
• Sequence Deletion
• Spain
• alpha-Globins (genetics)
• delta-Globins (genetics)
• delta-Thalassemia (blood, diagnosis, genetics)