Wildmann C, Larondelle Y, Vaerman J L, Eeckels R, Martiat P, Philippe M
Department of Clinical Biology, University of Louvain, Brussels, Belgium.
Hemoglobin. 1993 Feb;17(1):19-30. doi: 10.3109/03630269308998882.
Nine asymptomatic members of a family of Belgian origin, spanning three generations, present typical features of heterozygous beta-thalassemia. Since no mutation was detected with a large panel of oligonucleotide probes, the thalassemia gene was investigated by direct sequencing of DNA segments amplified by the polymerase chain reaction. A T-->C transition was detected in the translation initiation codon (ATG). The mutation, which abolishes an Nco I restriction site, was further confirmed by enzymatic digestion as well as by dot-blot hybridization of the amplified products with allele-specific oligonucleotide probes. It produced a beta zero-thalassemia phenotype characterized by marked microcytosis and hypochromia, as well as by an in vitro beta/alpha chain synthesis ratio close to O.5. Search for haplotype linkage showed the mutation to be associated with haplotype IX [- + - + + + +].
