Screening of Iranian thalassemic families for the most common deletions of the beta-globin gene cluster

Hemoglobin. 2007;31(4):463-9. doi: 10.1080/03630260701641286.

Abstract

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.

MeSH terms

  • Adolescent
  • Adult
  • Child, Preschool
  • Cohort Studies
  • DNA Mutational Analysis
  • Family
  • Female
  • Fetal Hemoglobin / genetics
  • Genetic Testing*
  • Genotype
  • Globins / genetics*
  • Hemoglobins, Abnormal / genetics
  • Humans
  • Iran
  • Male
  • Middle Aged
  • Multigene Family
  • Mutation*
  • Phenotype
  • Sequence Deletion*
  • beta-Thalassemia / genetics*

Substances

  • Hemoglobins, Abnormal
  • Globins
  • Fetal Hemoglobin
  • hemoglobin Lepore