摘要:

During a routine program of hemoglobin screening performed in the United Arab Emirates, we observed an electrophoretically fast-moving variant in a 9-month-old girl and in several members of her family. The structural determination, performed by reversed phase high performance liquid chromatography and amino acid sequencing, revealed a new variant that we named Hb A1-Ain Abu Dhabi [δ18(A16) Gly→Asp]. Its functional properties were normal.

ISSN:0363-0269    

DOI:10.3109/03630269209005687

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

摘要:

Clinical, hematologic, and molecular genetic studies are reported for five families with SS patients having unusually high fetal hemoglobin (Hb F) levels (mean 28.3%, range 19–42%). Some of the individuals were symptom-free and one was not anemic. However, some were symptomatic despite a very high Hb F. Neither the Hb F level nor the F cell distribution entirely explained the variation in clinical seventy. Molecular genetic studies identified the Senegal haplotype with the associated -158Gγ(C→T) mutation in two of the five families. The -202Gγ(C→G) mutation was not found in any of the individuals studied. Sequencing of theγ-globin gene promoters to detect genetic high F determinants not detectable by restriction digestion was not performed. All AS parents and AS siblings demonstrated elevated F cells when the Senegall-158Gγ(C→T) mutation was present with either theβsorβAallele. Double heterozygosity for two different high F determinants in some SS patients is suggested by the studies in at least one family. Discordance among siblings in clinical and hematologic manifestations in two families provides additional evidence for loci regulating Hb F cell production which are not linked to theβ-globin gene clusters.

ISSN:0363-0269    

DOI:10.3109/03630269209005688

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

摘要:

We have developed a rapid and simple approach for the molecular characterization of hemoglobin variants by a one-step reverse transcription-polymerase chain reaction of reticulocyte mRNA and direct sequencing of the product. This method can selectively amplify theα.1- orα.2-globin gene or theβ-globin gene transcript. The amino acid substitution of Hb G-Taichung is due to a G→C mutation at codon 74 of theα1-lobin gene, that of Hb J-Meinung to a G→A substitution at codon 56 of theβ-globin gene, and that of Hb Kaohsiung (or New York) to a T→A substitution at codon 113 of theβ-globin gene. The amplified segment encompassed the sequence from upstream of the initial codon behind the Cap site to downstream of the terminal codon before the polyadenylation addition signal. Hence, all hemoglobin variants should be able to be characterized by this approach.

ISSN:0363-0269    

DOI:10.3109/03630269209005689

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

摘要:

We have identified a second baby with the fetal methemoglobin F-M-Fort Ripley. It was observed in a Caucasian infant from Canada; at least eleven additional members of that family were known to have had a neonatal cyanosis similar to that seen in the propositus and in a previously described baby (2). Sequencing of amplified DNA that included (part of) the Gγgene greatly facilitated the characterization. The Gγx chain was readily isolated by reversed phase high performance liquid chromatography; its quantity was∼12.5% of totalγ. Interestingly, the baby also carried the AγT mutation on one chromosome, either in cis or in trans to the Gγx mutation. Hb F-M-Fort Ripley could be isolated in reasonably pure form by DEAE-cellulose chromatography. The isolated Hb Fx was unstable, had spectral changes characteristic for the M-hemoglobins, while its methemqglobin derivative reacted rapidly with cyanide. Oxygen affinity data could not be obtained. It is suggested that the formation of a rather large amount (∼25%) of mixed hybrids (α2GγX.γ) with low oxygen affinity is the main cause for the occurrence of the neonatal cyanosis.

ISSN:0363-0269    

DOI:10.3109/03630269209005690

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

ISSN:0363-0269    

DOI:10.3109/03630269209005691

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

ISSN:0363-0269    

DOI:10.3109/03630269209005692

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

ISSN:0363-0269    

DOI:10.3109/03630269209005693

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

ISSN:0363-0269    

DOI:10.3109/03630269209005694

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

ISSN:0363-0269    

DOI:10.3109/03630269209005695

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor

ISSN:0363-0269    

DOI:10.3109/03630269209005696

出版商:Taylor&Francis    

年代:1992

数据来源: Taylor