摘要:

The present review provides a summary of quantitative hemoglobin data and lists the results of gene mapping and sequencing analyses for blood samples from newborn babies of different countries. Methodology suitable for such studies is reviewed, various abnormal fetal hemoglobins are discussed, the occurrence of Hb Bart's (γ4) and of the embryonic chain is evaluated, and the various types ofγ-globin gene rearrangements (−Aγ. Aγ-;−Gγ. Gγ-;γ-thalassemia;γ-globin gene triplications, quadruplications, and quintuplications) are compared. The several tables list the frequencies of the common AγT variant and of the differentγgene rearrangements in various populations, while the results of quantitative analyses suggest that most anomalies are not associated with disease.

ISSN:0363-0269    

DOI:10.3109/03630269108998857

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

摘要:

We have determined the structural abnormality of a putative Hb E detected in an African-American family with no apparent Asian ancestry. The tryptic peptide map performed by high performance liquid chromatography showed that the electrophoretic variant was indeed Hb E [β26 (B8)Glu→Lys]. In addition, the tryptic map showed an abnormal peptide adjacent to theαT-6 peptide. The amino acid analysis and confirmatory restriction analysis of the DNA showed that a second mutation was also present, characterized by a substitution of arginine for lysine at residue 56 of the a chain. The variant is clinically silent and has been named Hb Port Huron for the city in Michigan where the family resides.

ISSN:0363-0269    

DOI:10.3109/03630269108998858

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

摘要:

There are three major African haplotypes associated with the sickle mutation: Benin (#19), Senegalese (#3), and Central African Repblic (#20). Previous studies have suggested that the Xmn I site (-158 bp 5′to theGγgene) is associated with elevated levels ofGγandwiththe Senegalesehaplotype, while other investigators questioned this association. In order to clarify theissue.we have determinedβhalotypes, tested fortlie presenceof theXninI site, and measured HbF andGγexpressionlevels in 143 AmericanBlackpatients with sickle cell anemia. Haplotypes were determined using eight polvmorphic sites in theβ-like globin gene cluster: Hinc II 5′toϵ, Hind III in IVS-IIGγandAγ, Hinc II within and 3′toφβ, Ava II in IVS-II ofβ, and Hpa I and Bani HI 3′toβ. TheGγ/Aγratio was analyzed by high performance liquid chromatography using a C18column. The Xmn I site was present in all 31chromosomes with the Sengalese haplotype. Of the remaining 255 chromosomes with other haplotypes, only 2 (0.8%) had the Xmn I site present. Therewas significant correlation between the presence of the Xmn I site and increasedGγ/Aγratio in a dose-dependent manner.The Hb F level was not significantly, increased in thepresence of the Xmn I site.The data indicate that the Xmn I site maintains aGγ/Aγratio typical of fetal life but does not necessarily cause elevation of Hb F. The latter seems to depend on factors other than the Xmn I site.

ISSN:0363-0269    

DOI:10.3109/03630269108998859

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

摘要:

A newδchain variant, Hb A2−Parkville [δ47(CD6)Asp→Val], has been identified in a female of Italian parentage. The mobility of the variant is less than carbonic anhydrase towards the anode at alkaline pH.

ISSN:0363-0269    

DOI:10.3109/03630269108998860

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

摘要:

In an effort to clarify the role of amino acid hydrophobicity at theβ6 position in sickling we have made recombinant hemoglobin tetramers containingβ6 Val (Hb S) andβ6 Leu (Hb Leu). Recombinant Hb S and Hb Leu had the same electrophoretic mobility, chromatographic behavior, and absorption spectrum. The deoxy form of both tetramers polymerized in high phosphate buffer (1.8 M) and exhibited distinct delay times prior to polymerization. The kinetics of polymerization.for recombinant and native Hb S were similar, while recombinant Hb Leu polymerized more readily. The solubility of deoxy Hb Leu was less than deoxy Hb S, indicating that rapid polymerization and decreased solubility of deoxyhemoglobin is accelerated with increasing hydrophobicity at theβ6 position.

ISSN:0363-0269    

DOI:10.3109/03630269108998861

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

ISSN:0363-0269    

DOI:10.3109/03630269108998862

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

ISSN:0363-0269    

DOI:10.3109/03630269108998863

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

ISSN:0363-0269    

DOI:10.3109/03630269108998864

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

ISSN:0363-0269    

DOI:10.3109/03630269108998856

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor