title: [Delta⁰-thalassemia by insertion of 27 base pairs in δ-globin gene with decreased hemoglobin A₂ levels].
abstract: 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.
  
  
  METHODS
  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.affiliation: Servicio de Bioquímica, Hospital de Jerez, Jerez, Cádiz, España.
authors.forename: Maria Luisa
authors.initials: ML
authors.lastname: González Borrachero
authors.affiliation: Servicio de Hematología y Hemoterapia, Hospital Clínico San Carlos, Madrid, España.
authors.forename: Félix
authors.initials: F
authors.lastname: de la Fuente-Gonzalo
authors.affiliation: Servicio de Hematología y Hemoterapia, Hospital Clínico San Carlos, Madrid, España.
authors.forename: Fernando Ataúlfo
authors.initials: FA
authors.lastname: González
authors.affiliation: Servicio de Hematología y Hemoterapia, Hospital Clínico San Carlos, Madrid, España.
authors.forename: Jorge M
authors.initials: JM
authors.lastname: Nieto
authors.affiliation: Servicio de Hematología y Hemoterapia, Hospital Clínico San Carlos, Madrid, España.
authors.forename: Ana
authors.initials: A
authors.lastname: Villegas
authors.affiliation: Servicio de Hematología y Hemoterapia, Hospital Clínico San Carlos, Madrid, España. Electronic address: paloma.ropero@salud.madrid.org.
authors.forename: Paloma
authors.initials: P
authors.lastname: Ropero
mesh_terms: D001483:Base Sequence; D015415:Biomarkers / Q000097:blood; D005260:Female; D006443:Hemoglobin A2 / Q000235:genetics / Q000378:metabolism*; D006455:Hemoglobins, Abnormal / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008875:Middle Aged; D016254:Mutagenesis, Insertional; D017384:Sequence Deletion; D013030:Spain; D055542:alpha-Globins / Q000235:genetics; D055546:delta-Globins / Q000235:genetics*; D055538:delta-Thalassemia / Q000097:blood / Q000175:diagnosis / Q000235:genetics*
chemical_list: D015415:Biomarkers; D006455:Hemoglobins, Abnormal; D055542:alpha-Globins; D055546:delta-Globins; C108106:hemoglobin Watts; D006443:Hemoglobin A2
keywords: Delta-talasemia; Delta-thalassemia; Diagnósticos moleculares; España; Hemoglobinopatías estructurales; Molecular diagnostics; Spain; Structural hemoglobinopathies