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T H Huisman

Publications and source records attributed to T H Huisman.

At least 109 records · Page 6Linked to original sources
PubMed1993

An IVS-I-117 (G-->A) acceptor splice site mutation in the alpha 1-globin gene is a nondeletional alpha-thalassaemia-2 determinant in an Indian population.

In 1991 we reported the identification of two deletional alpha-thalassaemia-2 determinants (-3.7 kb and -4.2 kb) and one nondeletional alpha-thalassaemia-2 determinant (Hb Koya Dora alpha 2 codon 142, TAA-->TCA) in a tribal population in Central India (Gupta et al, 1991). Evidence was obtained at that time for the possible presence of an additional nondeletional alpha-thalassaemia-2 because of low levels of Hb S (< 28%) in some Hb S heterozygotes with a simple alpha-thalassaemia-2 heterozygosity (-alpha/alpha alpha). This abnormality has now been identified as a G-->A mutation at IVS-I-117 of the alpha 1-globin gene (acceptor splice site) which makes this gene nonfunctional. Its frequency was established at approximately 6% which raises the total frequency of alpha-thalassaemia determinants in this population to approximately 60%. Subjects with a deletional alpha-thalassaemia-2 and the newly discovered alpha 1 acceptor splice junction mutation in trans appear to have an alpha chain deficiency similar to that of an alpha-thalassaemia-2 homozygote (-alpha/-alpha). An additional change (C-->G) at the Cap -4 site was observed in six alpha 1- and one alpha 2-globin genes; this polymorphism is not associated with a decrease in alpha chain synthesis and is not linked to the IVS-I-117 (G-->A) mutation.

Adolescent↗
PubMed1993

Level of fetal hemoglobin in children with sickle cell anemia: influence of gender, haplotype and alpha-thalassemia-2 trait.

We have evaluated hematological data for numerous blood samples collected from 51 sickle cell anemia (SS) patients during their first 10 years of life. Haplotypes and alpha-globin gene status were determined in all patients. A total of 482 hematological evaluations and 317 fetal hemoglobin (Hb F) determinations are presented. The data show that the Hb F levels are the highest in patients with haplotypes 3/3 and the lowest in those with haplotypes 20/20. This is reflected in differences in total hemoglobin, PCV value, and RBC counts, which are the lowest in the 20/20 group and the highest in the 3/3 group. Female SS patients with haplotypes 19/19 have higher Hb F levels than their male counterparts; the same was observed for the patients with the 19/3 haplotype combination but not for those with the 20/3 haplotype combination. A concomitant alpha-thalassemia-2 heterozygosity had little or no effect on the hemoglobin level. The data confirm that SS children, aged 1-10 years, with a homozygosity for haplotype No. 20 are most severely affected by their disease.

Anemia, Sickle Cell↗
PubMed1993

Three sickle cell anemia patients each with a different alpha chain variant. Diagnostic complications.

We have studied three sickle cell anemia patients who also carried a heterozygosity for one of the following alpha chain abnormalities: Hb G-Philadelphia [alpha 68(E17)Asn-->Lys], Hb Montgomery [alpha 48 (CE6)Leu-->Arg], and Hb Chicago [alpha 136(H19)Leu-->Met]. Electrophoretic analyses alone may result in incomplete and incorrect information. Confirmation of the diagnosis of Hb SS or Hb SC disease by one of the fast high performance liquid chromatographic procedures is recommended.

Adult↗
PubMed1993

Hb Hradec Kralove (Hb HK) or alpha 2 beta 2 115(G17)Ala-->Asp, a severely unstable hemoglobin variant resulting in a dominant beta-thalassemia trait in a Czech family.

We have identified through sequencing of amplified DNA a GCC-->GAC mutation in codon 115 of the beta-globin gene in a mother and daughter of a small Czech family. This base change was confirmed by hybridization with a 32P-labeled specific oligonucleotide probe and by gene mapping because it creates a new Ava II site. The mutation results in an Ala-->Asp replacement at beta 115(G17); this beta chain is severely unstable and could not be identified either as chain or as hemoglobin variant by isoelectrofocusing and various high performance liquid chromatography methods. Stability tests were mildly positive in freshly prepared lysates, but an unstable hemoglobin could not be detected in older lysates with these methods. Its presence results in a dominant type of beta-thalassemia in the two heterozygotes, with moderate anemia, reticulocytosis, nucleated red cells, target cells, and other red cell changes, Heinz body formation, and splenomegaly; the oldest of the two patients was splenectomized. Both subjects had a marked increase in fetal hemoglobin synthesis.

Adult↗
PubMed1993

Black alpha-thalassemia-1: partial characterization of an approximately 80 kb deletion which includes the zeta- and alpha-globin genes.

A large novel alpha-thalassemia-1 deletion which includes the zeta-, alpha 2-, alpha 1-, and theta 1-globin genes is described in a Black family living in Georgia and Florida. The deletion which was characterized by restriction enzyme analysis, extends 15 to 35 kb 5' and at least 35 kb 3' to the Cap site of the zeta-globin gene. Mental retardation was not observed. The deletion was present in a 35-year-old male with Hb H disease and his mother; the major hemoglobin type in the propositus was Hb G-Philadelphia or alpha (2)68(E12)Asn-->Lys beta 2 because his second chromosome carried the -alpha G(-3.7 kb) alpha-thalassemia-2 deletion.

Adolescent↗
PubMed1993

Allele-specific amplification for the identification of several hemoglobin variants.

Eight known abnormal hemoglobins in more than 40 patients have been identified with an allele-specific amplification procedure. These are mutants of the A gamma (Hb F-Sardinia), the delta (Hb B2), the alpha (Hb G-Philadelphia), and the beta (Hbs S, C, E, D-Los Angeles, O-Arab) globin genes. Adjustment to an unusually high annealing temperature improves the procedure greatly, allowing excellent discrimination between normal and mutant alleles, irrespective of the particular mismatch. The discrimination includes the Hbs C and E in the same reaction mixture-multiplex allele-specific amplification. The procedure can successively use primers with 3'-penultimate critical nucleotides, degenerative ends, and potentially dimerizing properties.

Alleles↗
PubMed1993

Posttranslational modification of beta 141 Leu associated with the beta 75(E19)Leu-->Pro mutation in Hb Atlanta.

The recent report of the oxidation of beta 141 Leu in a New Zealand family with Hb Atlanta [ beta 75(E19)Leu-->Pro] prompted us to reinvestigate the original Hb Atlanta case from Georgia. Tryptic peptide maps showed that the modified beta CoT-14 peptide was present together with beta AT-14 in isopropanol precipitates of Hb Atlanta. Amino acid analysis confirmed that beta CoT-14 lacked leucine and mass spectrometry indicated that it had an increased mass of 16 Daltons. These findings support the proposition that the beta 75 Leu-->Pro substitution in the E helix is the direct cause of the beta 141 Leu oxidation.

Amino Acid Sequence↗
PubMed1993

Beta-thalassemia mutations in the Portuguese; high frequencies of two alleles in restricted populations.

We report the characterization of seven different beta-thalassemia mutations in 131 newly diagnosed Portuguese beta-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 the beta-thalassemia alleles in this population. The geographical distribution is uneven; the TGG-->TGA mutation at codon 15 was primarily observed in the coastal region north of Lisbon, while the IVS-I-6 (T-->C) mutation was confined to the central part of the country.

Alleles↗
PubMed1993

Usefulness of HPLC methodology for the characterization of combinations of the common beta chain variants Hbs S, C, and O-Arab, and the alpha chain variant Hb G-Philadelphia.

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 different beta chain variants and the alpha chain 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 various alpha and beta chains; 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 additional alpha-thalassemia-2 heterozygosity or homozygosity.

Adult↗
PubMed1993

Hb Alesha or alpha 2 beta (2)67(E11)Val-->Met: a new unstable hemoglobin variant identified through sequencing of amplified DNA.

We have identified a valine-->methionine mutation at position 67 of the beta chain in the hemoglobin of a young Russian patient with severe hemolytic disease, anemia, splenomegaly, Heinz body formation, and continued requirement for blood transfusions despite an early splenectomy. Sequencing of amplified DNA readily identified a GTG-->ATG mutation at codon 67. The introduction of the larger methionine residue into the heme pocket, and the loss of the bonds between valine at beta 67 and the heme group, adequately account for the severe instability of Hb Alesha and the serious clinical condition of its carrier.

Anemia, Hemolytic, Congenital↗