title: Molecular Characterization of δ-Thalassemia in Iran.
abstract: δ-Thalassemia (δ-thal) (OMIM #142000) resulting from mutations on the HBD gene usually has no clinical consequences. However, it may cause the misdiagnosis of β-thalassemia (β-thal) carriers by lowering the Hb A2 level to the normal range. Therefore, a study for δ-thal should be considered as a step in the detection of at-risk couple in our region. The aim of the present study was to characterize the mutations of the HBD gene in β-thal carriers with normal Hb A2 levels, and also in normal individuals with Hb A2 of less than 2.0%. Four β-thal carriers with normal Hb A2 and 39 individuals with Hb A2 of less than 2.0% were enrolled. Genomic DNA was extracted by the salting out method and the HBD gene was investigated by polymerase chain reaction (PCR) and direct DNA sequencing. Hb A2-Yialousa (HBD: c.82 G > T) was the most common variant found in the HBD gene, but the following mutations were also found: Hb A2-NYU (HBD: c.39 T > A), Hb A2-Coburg (HBD: c.350 G > A), Hb A2-Etolia (HBD: c.257 T > C), Hb A2-Fitzroy (HBD: c.428 C > A) and the δ-IVS-I-5 (G > T) (HBD: c.92 + 5 G > T). One case was a compound heterozygote for δ-IVS-I-5/Hb A2-Fitzroy. The results of this single center study suggest that the mutations in the HBD gene in the Iranian population are heterogeneous and should be considered in genetic counseling of families.
authors.affiliation: a Department of Molecular Medicine , Biotechnology Research Centre, Pasteur Institute of Iran , Tehran , Iran.
authors.forename: Alireza
authors.initials: A
authors.lastname: Kordafshari
authors.affiliation: a Department of Molecular Medicine , Biotechnology Research Centre, Pasteur Institute of Iran , Tehran , Iran.
authors.forename: Azam
authors.initials: A
authors.lastname: Amirian
authors.affiliation: a Department of Molecular Medicine , Biotechnology Research Centre, Pasteur Institute of Iran , Tehran , Iran.
authors.forename: Sirous
authors.initials: S
authors.lastname: Zeinali
authors.affiliation: a Department of Molecular Medicine , Biotechnology Research Centre, Pasteur Institute of Iran , Tehran , Iran.
authors.forename: Atefeh
authors.initials: A
authors.lastname: Valaei
authors.affiliation: a Department of Molecular Medicine , Biotechnology Research Centre, Pasteur Institute of Iran , Tehran , Iran.
authors.forename: Fereshteh
authors.initials: F
authors.lastname: Maryami
authors.affiliation: a Department of Molecular Medicine , Biotechnology Research Centre, Pasteur Institute of Iran , Tehran , Iran.
authors.forename: Morteza
authors.initials: M
authors.lastname: Karimipoor
mesh_terms: D005838:Genotype; D006443:Hemoglobin A2 / Q000235:genetics*; D006455:Hemoglobins, Abnormal / Q000235:genetics; D006801:Humans; D007492:Iran / Q000453:epidemiology; D009154:Mutation; D055538:delta-Thalassemia / Q000453:epidemiology* / Q000235:genetics*
chemical_list: D006455:Hemoglobins, Abnormal; C106312:hemoglobin A2 Etolia; D006443:Hemoglobin A2; C039470:hemoglobin NYU; C043005:hemoglobin A2 Fitzroy
keywords: Hb A2; Iran; point mutation(s); δ-Thalassemia (δ-thal)