Screening of Iranian thalassemic families for the most common deletions of the beta-globin gene cluster.
Deltabeta-thalassemia (thal) is a disorder, characterized by increased levels of fetal hemoglobin (Hb F) in adult life. A considerable number of deletions of variable size and position in the beta-globin gene cluster are associated with the clinical manifestation of deltabeta-thal. In this study we have determined the presence of the eight most common deletions in Iranian patients. Thirty-two patients from 19 families were referred to the Kariminejad-Najmabadi Pathology and Genetics Center, Tehran, Iran (a private genetics center), within the past 3 years with elevated levels of Hb F and low mean corpuscular volume (MCV). After obtaining their informed consent, DNA was extracted from whole blood by the salting-out method. Detection of eight deletions was performed using polymerase chain reaction (PCR). These deletions included the hereditary persistence of fetal Hb (HPFH) 1 (Black) and 3 (Indian), Spanish (-114 kb), Sicilian (-13,377 bp), Chinese (G)gamma((A)gammadeltabeta)(0)-thal (-100 kb), Asian-Indian inversion-deletion (G)gamma((A)gammadeltabeta)(0)-thal, and the Turkish form of inversion-deletion (deltabeta)(0)-thal, as well as the Hbs Lepore, which are characterized by unequal crossovers between the delta- and beta-globin genes. We found the Sicilian (-13,377 bp) and Hb Lepore deletions as well as the Asian-Indian (G)gamma((A)gammadeltabeta)(0)-thal in 11 (57.89%), three (15.78%) and five (26.31%) families, respectively. None of the aforementioned deletions were found in one of the patients. This is the first study of the deletions involved in deltabeta-thal in Iranian patients. Our study highlights the importance of detecting these mutations for prenatal diagnosis carrier detection and genotype/phenotype prediction.
Esteghamat
Fatemehsadat
F
Kariminejad-Najmabadi Pathology and Genetics Center, Tehran, Iran.
Imanian
Hashem
H
Azarkeivan
Azita
A
Pourfarzad
Farzin
F
Almadani
Navid
N
Najmabadi
Hossein
H
D000293:Adolescent; D000328:Adult; D002675:Child, Preschool; D015331:Cohort Studies; D004252:DNA Mutational Analysis; D005190:Family; D005260:Female; D005319:Fetal Hemoglobin / Q000235:genetics; D005820:Genetic Testing; D005838:Genotype; D005914:Globins / Q000235:genetics*; D006455:Hemoglobins, Abnormal / Q000235:genetics; D006801:Humans; D007492:Iran; D008297:Male; D008875:Middle Aged; D005810:Multigene Family; D009154:Mutation; D010641:Phenotype; D017384:Sequence Deletion; D017086:beta-Thalassemia / Q000235:genetics*
D006455:Hemoglobins, Abnormal; D005914:Globins; D005319:Fetal Hemoglobin; C037659:hemoglobin Lepore