A novel alpha-thalassemia nonsense mutation in codon 23 of the alpha2-globin gene (GAG-->TAG) in a Tunisian family

Hemoglobin. 2004 Aug;28(3):249-54. doi: 10.1081/hem-120040258.

Abstract

Herein we describe a novel alpha-thalassemia (thal) point mutation in the alpha2-globin gene, found in a 3-year-old Tunisian girl who had Hb Bart's (gamma4) at birth, later on presenting with moderate anemia, microcytosis and hypochromia. She had a normal Hb A2 level and no abnormal hemoglobin (Hb) fraction. After excluding most of the common Mediterranean mutations, the alpha2-globin gene was sequenced and found to have a point mutation in the heterozygous state that creates a premature stop signal for translation (GAG-->TAG or Glu-->Term) at codon 23. The same mutation was also found in the mother in the heterozygous state, while the father had a normal sequence. The presence of the mutation was also confirmed by nucleotide sequencing of the opposite strand. Since the mutation creates a restriction site for the BfaI enzyme, a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP)-based assay was established for screening purposes.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Anemia, Hypochromic / genetics
  • Child, Preschool
  • Codon / genetics*
  • Codon, Nonsense*
  • DNA Mutational Analysis
  • Family
  • Female
  • Genetic Testing
  • Globins / genetics*
  • Heterozygote*
  • Humans
  • Male
  • Polymorphism, Restriction Fragment Length
  • Tunisia
  • alpha-Thalassemia / genetics*

Substances

  • Codon
  • Codon, Nonsense
  • Globins