摘要:

The recent report of the oxidation ofβ141 Leu in a New Zealand family with Hb Atlanta [β75(E19)Leu→Pro] prompted us to reinvestigate the original Hb Atlanta case from Georgia. Tryptic peptide maps showed that the modifiedβCOT-14 peptide was present together withβAT-14 in isopropanol precipitates of Hb Atlanta. Amino acid analysis confirmed thatβCOT-14 lacked leucine and mass spectrometry indicated that it had an increased mass of 16 Dal tons. These findings support the proposition that theβ75 Leu→Pro substitution in the E helix is the direct cause of theβ141 Leu oxidation.

ISSN:0363-0269    

DOI:10.3109/03630269308998880

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

We detected Hb D-Los Angeles [β121(GH4)Glu→Gln], the most common hemoglobin variant after Hb S and Hb Lepore-Boston, in six unrelated families in Southern Italy. Ten patients were studied; eight patients were heterozygotes and two were compound heterozygotes for the hemoglobin variant and theβ-thalassemia codon 39 (C→T) nonsense mutation. Theβ-globin gene sequence was characterized by polymerase chain reaction direct sequencing; restriction fragment length polymorphisms were defined by Southern blot analysis. The gene variant, due to the GAA→CAA substitution at codon 121, was found in association with the 5′subhaplotype [+—] and theβ-globin gene framework 1; in addition, it was found to be associated with the absence of Ava II/Φβand Xmn 1/5′Gγ, and with the presence of Hpa 1/3′β. This restriction fragment length polymorphism haplotype is common in the Mediterranean area as well as in other populations. The findings are equally compatible with an independent origin in the Mediterranean area or with origin in Asia and subsequent spread to Italy.

ISSN:0363-0269    

DOI:10.3109/03630269308998881

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

Nine asymptomatic members of a family of Belgian origin, spanning three generations, present typical features of heterozygousβ-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 aβ0-thalassemia phenotype characterized by marked microcytosis and hypochromia, as well as by an in vitroβ/αchain synthesis ratio close to 0.5. Search for haplotype linkage showed the mutation to be associated with haplotype IX [−+−+ +].

ISSN:0363-0269    

DOI:10.3109/03630269308998882

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

We report the characterization of seven differentβ-thalassemia mutations in 131 newly diagnosed Portugueseβ-thalassemia heterozygotes. Methodology included the detection of abnormal fragments by agar gel electrophoresis of PCR-amplified DNA fragments after digestion with specific restriction endonucleases, as well as hybridization with synthetic nucleotide probes and sequencing of amplified DNA. Four mutations, including the newly discovered TGG→TGA change at codon 15, occurred in excess of 10% and accounted for some 90% of theβ-thalassemia alleles in this population. The geographical distribution is uneven; the TGA→TGA mutation at codon 15 was primarily observed in the coastal region north of Lisbon, while the IVS-1-6 (T→C) mutation was confined to the central part of the country.

ISSN:0363-0269    

DOI:10.3109/03630269308998883

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

The present paper reports on the application of a simple micromethod for quantitation of total and fetal hemoglobin in small volumes of diluted erythroid cell hemolysates. A modified alkaline denaturation procedure was used to denature and precipitate non-fetal hemoglobins and the tetramethylbenzidine procedure was used for quantitation of the soluble hemoglobin. Using a combination of these procedures, total hemoglobin concentrations as low as 0.2 mg% (2μg/ml) and a fetal hemoglobin proportion of 0.5% could be reliably determined. We have utilized this procedure to study two aspects of hemoglobin production in human erythroid cells grown in culture; the proportion of fetal hemoglobin of cells in culture as compared to that in the peripheral blood of the donors, and the kinetics of hemoglobin production during maturation of these cultured cells. The results show that the cultured erythroid cells have a hemoglobin phenotype similar to the individual from whom they are derived and that erythroid differentiation may be studied in vim in these cultured cells by measurement of these and other parameters.

ISSN:0363-0269    

DOI:10.3109/03630269308998884

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

摘要:

We have analyzed the blood samples from seven members of two families that contained mixtures of different hemoglobin types due to the simultaneous presence of differentβchain variants and theαchain variant Hb G-Philadelphia. The methods used were isoelectrofocusing and cation exchange high performance liquid chromatography for the separation of the hemoglobin components, and reversed phase high performance liquid chromatography for that of the variousαandβchains; the chromatographic procedures also provided quantitative data. Application of these fast and simple high performance liquid chromatographic methods greatly aided in defining the different hemoglobinopathies that were present in these persons, including an additionalα-thalassemia-2 heterozygosity or homozygosity.

ISSN:0363-0269    

DOI:10.3109/03630269308998885

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

ISSN:0363-0269    

DOI:10.3109/03630269308998886

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

ISSN:0363-0269    

DOI:10.3109/03630269308998887

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

ISSN:0363-0269    

DOI:10.3109/03630269308998888

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor

ISSN:0363-0269    

DOI:10.3109/03630269308998889

出版商:Taylor&Francis    

年代:1993

数据来源: Taylor