alpha-thalassaemia masked by beta gene defects and a new polyadenylation site mutation on the alpha2-globin gene

Eur J Haematol. 2010 Apr;84(4):354-8. doi: 10.1111/j.1600-0609.2009.01380.x. Epub 2009 Nov 12.


We report three examples of chronic anaemia involving complex combinations of alpha- and beta-globin gene defects. The first case had a potential Hb H disease caused by the classic SEA/RW deletions masked by Hb E [beta26(B8)Glu-->Lys] in the homozygous state. The second had an unusual Hb H disease caused by compound heterozygosity for two different alpha2 polyadenylation site mutations masked by a beta-thalassaemia heterozygosity. The third had an intermediate alpha-thalassaemia with considerable anaemia caused by an as yet unknown polyadenylation site (AATAAA>AATAAC) mutation in combination with a common RW deletion masked by a common Hb C [beta6(A3)Glu-->Lys] heterozygosity. Diagnostic methods, genotype/phenotype correlations and the chance of overlooking these combinations during risk assessment in a multiethnic society are discussed.

Publication types

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

MeSH terms

  • Adult
  • Female
  • Hemoglobins, Abnormal / genetics
  • Heterozygote
  • Homozygote
  • Humans
  • Middle Aged
  • Mutation*
  • RNA 3' Polyadenylation Signals / genetics*
  • alpha-Globins / genetics*
  • alpha-Thalassemia / diagnosis
  • alpha-Thalassemia / genetics*
  • beta-Globins / genetics*
  • beta-Thalassemia / genetics


  • Hemoglobins, Abnormal
  • alpha-Globins
  • beta-Globins