Comprehensive spectrum of the β-Thalassemia mutations in Khuzestan, southwest Iran.
β-Thalassemia (β-thal) is characterized by reduction or absence of β-globin gene expression. We describe the spectrum of mutations observed in a large cohort of β-thal carriers in Khuzestan, Southwest Iran. All together 1,241 blood samples from individuals with decreased mean corpuscular volume (MCV) and elevated Hb A(2) levels, were analyzed either by reverse dot-blot or by direct sequencing of the HBB gene. We found 42 different mutations associated with β-thal and identified eight common β-globin variants, namely, Hb S [β6(A3)Glu→Val], Hb C [β6(A3)Glu→Lys], Hb D-Punjab [β121(GH4)Glu→Gln] and Hb O-Arab [β121(GH4)Glu→Lys]. No mutations were found in two individuals. The distribution is characteristic of a heterogenous population with three preferential mutations being present [codons 36/37 (-T), IVS-II-1 (G>A) and IVS-I-110 (G>A)] at a frequency of 20.5, 20.0 and 14.2%, respectively, followed by 39 mutations in decreasing frequencies from 5.2 down to 0.1%. These data are of importance when planning prevention strategies in the country.
Galehdari
Hamid
H
Gene Test Laboratory, Shafa Hospital, Ahwaz, Iran. galehdari187@yahoo.com
Salehi
Bahaoddin
B
Azmoun
Somaiyeh
S
Keikhaei
Bijan
B
Zandian
Khoda Morad
KM
Pedram
Mohammad
M
D004252:DNA Mutational Analysis; D017931:DNA Primers; D005787:Gene Frequency; D005838:Genotype; D005843:Geography; D006451:Hemoglobin, Sickle / Q000235:genetics; D006455:Hemoglobins, Abnormal / Q000235:genetics; D006801:Humans; D007492:Iran; D009154:Mutation; D016133:Polymerase Chain Reaction / Q000379:methods; D055544:beta-Globins / Q000235:genetics*; D017086:beta-Thalassemia / Q000235:genetics*
D017931:DNA Primers; D006451:Hemoglobin, Sickle; D006455:Hemoglobins, Abnormal; D055544:beta-Globins; C026237:hemoglobin D Punjab; C032031:hemoglobin Arab