Two novel polyadenylation mutations leading to beta(+)-thalassemia

Br J Haematol. 1990 May;75(1):122-6. doi: 10.1111/j.1365-2141.1990.tb02627.x.


In an ongoing effort to identify point mutations causing beta-thalassaemia, we have found two previously unreported mutations which are located in the Poly A site of the beta-globin gene. The screening programme used amplified DNA and dot-blot hybridization with several 32P-labelled oligonucleotide probes. DNA samples which remained unidentified by this methodology were subjected to sequencing with 32P-labelled primers and modified T7 DNA polymerase. The newly discovered mutations were confirmed by the dot-blot hybridization technique. One type concerned an AATAAA----AATGAA mutation in the polyadenylation site and was found in one family from Yugoslavia (including one patient with the C----T mutation at codon 29 in trans), one from Bulgaria (the patient had the G----A mutation at IVS-I-110 in trans), and one from Greece (this patient had the C----G mutation at IVS-II-745 in trans). Haematological data for three simple heterozygotes suggested a rather mild beta(+)-thalassemia. The second type involved an AATAAA----AATAGA mutation and was found in one family from Malaysia. The propositus had the beta E mutation on the other chromosome, was originally diagnosed as mild Hb E-beta(+)-thalassaemia, and had Hb A and Hb E percentages which were nearly the same.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Base Sequence
  • Child
  • Child, Preschool
  • DNA Mutational Analysis
  • Family
  • Female
  • Globins / genetics*
  • Humans
  • Male
  • Middle Aged
  • Molecular Sequence Data
  • Mutation*
  • Poly A / genetics*
  • Thalassemia / genetics*


  • Poly A
  • Globins