Hb F-Forest Park, a new A gamma variant with two amino acid substitutions, 75(E19)Ile----Thr and 73(E17)Asp----Asn, which can be identified in adults by gene-mapping analysis

The discovery is reported of a new fetal hemoglobin (Hb) variant which has an abnormal A gamma globin chain with two substitutions, namely 73(E17) Asp----Asn and 75(E19) Ile----Thr (the latter is also seen in the common A gamma T chain). This A gamma T variant was present in a female Caucasian newborn; its quantity at birth was 12.2% of the total Hb F (including F, F1 and F-Forest Park). Extensive gene-mapping analyses with a battery of restriction enzymes and probes identified normal globin gene arrangements in the baby and several relatives, but a -G gamma-G gamma-globin gene arrangement was present in the father, paternal grandmother and half-sister. The Hb F-Forest Park anomaly could be detected in the father, paternal grandfather, half-brother and the baby through digestion of their DNA's with SfaNI and hybridization with the gamma IVS-II probe, because the G----A base substitution at codon 73 leads to loss of a restriction site and to the occurrence of an abnormal fragment.

Hb Doha or alpha 2 beta 2[X-N-Met-1(NA1)Val----Glu]; a new beta-chain abnormal hemoglobin observed in a Qatari female

Structural analysis of a fast-moving hemoglobin variant, present in three members of a Qatari family, identified a Val----Glu substitution at position 1 (NA1) of the beta-chain. The introduction of this glutamic acid residue prevents the removal of the initiator methionine, thus extending the N-terminus by one residue to Met-Glu-His-Leu-Thr-. The methionine residue is blocked by an as yet not completely identified molecule. The presence of the variant in a heterozygote does not have clinical consequences.

Hb Regina or alpha 2 beta 2 96(FG3)Leu----Val: a high oxygen affinity variant discovered by cation-exchange HPLC

Results are reported of studies of the hemoglobin from one member of a Canadian family with a mild erythrocytosis. This variant, which accounted for about 40% of the hemoglobin, could be separated from Hb A and Hb A2 by cation-exchange chromatography. Micro methodology allowed the characterization of a Leu----Val replacement at position beta 96(FG3). Hb Regina has an increased oxygen affinity, which adequately explains the hematological observations.

Hb F-Tokyo or alpha 2G gamma 2 34(B16)Val----Ile, a silent gamma chain variant detected by reverse phase high performance liquid chromatography

Hb F-Tokyo with a Valine----Isoleucine replacement at position gamma 34(B16) is a G gamma chain variant which was discovered by reverse phase chromatography as this method permitted the nearly complete separation of the three types of gamma chain. The chemical characterization was greatly facilitated by the use of a larger, preparative, HPLC column which allowed the isolation of sufficient quantities of the different gamma chains.

Quantitation of hemoglobin components by high-performance cation-exchange liquid chromatography: its use in diagnosis and in the assessment of cellular distribution of hemoglobin variants

Additional data are presented that were obtained with a newly developed cation-exchange high-performance liquid chromatography (HPLC) method allowing the separation of numerous normal and abnormal human hemoglobin types. The method was found to be of considerable value for the diagnosis of certain hemoglobinopathies in the adult as well as in the newborn. Definitive differentiation between, AS, SS, S-beta+-thal, SD, SC, AC, C-beta+-thal, etc in cord bloods was readily accomplished even when the samples were collected on filter paper. Analyses of the hemoglobin in cells from Hb S and Hb C heterozygotes with different numbers of alpha chain genes (alpha alpha/alpha alpha; -alpha/alpha alpha; -alpha/-alpha) after separation by a Dextran density centrifugation technique failed to show significant changes in the relative quantitation of the variant hemoglobin types. Glycosylation of hemoglobin increased greatly with an increase in red cell age. Similar analyses of red cells from a young girl with Hb S trait and Hb H disease (the --/-alpha genic arrangement) gave comparable data. Some indication was obtained that her youngest cells contained some of the beta A4 and beta S4 tetrameric hemoglobins.

Hb J-Singa (alpha-78 Asn leads to Asp), a newly discovered hemoglobin variant with the same amino acid substitution as one of the two present in Hb J-Singapore (alpha-78 Asn leads to, alpha-79 Ala leads to Gly)

A new fast-moving alpha-chain Hb variant with an Asn leads to Asp substitution at position alpha-78 was found in a French-Acadian family living in Eastern Canada. The identical substitution was reported in Hb J-Singapore, which also had an additional Ala leads to Gly substitution at position alpha-79. The new variant, which did not result in any clinical symptoms, was named accordingly, Hb J-Singa.