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.

Heterogeneity in the molecular basis of three types of hereditary persistence of fetal hemoglobin and the relative synthesis of the G gamma and A gamma types of gamma chain.

Restriction endonuclease analyses of DNA from one Black G gamma A gamma-HPFH homozygote and four Black and one Indian G gamma A gamma-HPFH heterozygotes have identified three different HPFH types which are the result of large deletions including the delta and beta genes. Two of the types are comparable to those characterized previously, but the third, which is present in the Indian heterozygote, shows a distinct difference in the size of the deletion. The 5' end point of the deletion in this type III G gamma A gamma-HPFH extends 0.

Hb Wayne, the frameshift variant with extended alpha chains observed in a Caucasian family from Alabama.

The presence of the alpha-globin frameshift mutant, Hb Wayne, in three generations of a second family is described. The data include a hematological evaluation of the four heterozygotes, structural characterization of the variant, the use of HPLC for the separation of tryptic and chymotryptic peptides, functional analyses of the isolated variant showing high affinity for oxygen and the (near) absence of a Bohr effect, and alpha chain gene organization analyses with restriction endonuclease technology suggesting that the Hb Wayne heterozygote has a full complement of four alpha globin genes.

A new high-performance liquid chromatographic procedure for the separation and quantitation of various hemoglobin variants in adults and newborn babies.

A new cation-exchange HPLC method is described for the separation and quantitation of abnormal human Hbs. The method makes use of Synchropak CM 300, a silica support with carboxylic acid residues, and Bis-Tris-KCN-Na-acetate developers and allows a completion of the chromatogram in 50 to 90 min depending on the sample to be analyzed. Specific chromatographic profiles have been obtained for several beta, alpha, and delta chain variants.

The distribution of fetal hemoglobin and the types of gamma chain in red cell fractions separated by gradient centrifugation from blood of patients with sickle cell anemia and other hemoglobinopathies.

Isopycnic separations of red cells from cord bloods, and from patients with sickle cell anemia, different forms of HPFH, S-beta O-thalassemia, and a beta +-thalassemia homozygosity were made in order to evaluate the distribution of Hb F and the relative levels of G gamma and A gamma chains over the cell fractions. As expected, the cord blood data showed decreased levels of both Hb-F and G gamma chains in the top cell fractions since the beta leads to gamma and high G gamma: A gamma low G gamma: A gamma switches are operative around the time of birth. Complete cell fractionations were made on the blood of three SS patients with low G gamma values (40%) and three SS patients with high G gamma values (60%).

Hb A2-Zagreb or alpha 2 delta 2(125)(H3)Gln replaced by Glu, a new delta chain variant in association with delta beta-thalassemia.

The structural identification of a new delta chain variant is described. The abnormal Hb A2 was found in two members of a family from Zagreb, Yugoslavia. The propositus also had a delta beta-thalassemia heterozygosity.

Hb A2-Manzanares or alpha 2 delta 2 121 (GH4) Glu replaced by Val, an unstable delta chain variant observed in a Spanish family.

A slowly moving variant of Hb A2 was present in a 25-year-old Spanish woman and her mother, and was found to have a Glu replaced by Val substitution at position 121 of the delta chain. The variant was unstable and precipitated gradually during anion exchange chromatography. The effect of this substitution on the stability of the protein is apparently more severe for Hb A2 than for Hb A because Hb Beograd (beta 121 Glu replaced by Val) has normal physicochemical properties.

Identification of hemoglobin G-Philadelphia (alpha 68 Asn replaced by Lys) and hemoglobin Matsue-Oki (alpha 75 Asp replaced by Asn) in a black infant.

Two alpha-chain variants, Hb G-Philadelphia and Hb Matsue-Oki, were present in members of a relatively large black family from South Carolina. The four Hb G-Philadelphia heterozygotes averaged 35.6% Hb G, suggesting the presence of an alpha-thalassemia-2 condition in cis to the Hb G mutation, which was confirmed by DNA structural analysis.

The heterogeneity of the gamma-chain of fetal hemoglobin in HbS heterozygotes.

The relative quantities of the three types of gamma chain (G gamma, A gamma I, A gamma T) were determined in 18 AS parents of selected SS patients, in 15 additional HbS heterozygotes, as well as in additional SS patients, and in 35 SS and 24 AS newborn babies. The low amount of HbF in all AS adults (less than 1%) made it necessary to further improve the isolation procedure of HbF, which was accomplished by introducing an HPL chromatographic method. The additional data for older SS patients confirmed the existence of two groups characterized by either low G gamma (40%) or high G gamma (60%) values in their HbF.

Hb A2-Canada or alpha 2 delta 2 99(G1) Asp replaced by Asn, a newly discovered delta chain variant with increased oxygen affinity occurring in cis to beta-thalassemia.

An Indian family is described in which the father has a delta chain abnormal hemoglobin which is the result of a mutation of the delta gene in cis to a beta-thalassemia heterozygosity. The abnormality concerns a substitution of the Asp residue in position 99 (G1) by an Asn residue. A similar substitution has been found in the beta chain of Hb Kempsey (alpha 2 beta 2 99 Asp replaced by Asn).

Hb F-Bonaire-Ga or alpha 2 A gamma 2 39(C5) Gln replaced by Arg, characterized by high pressure liquid chromatographic and microsequencing procedures.

A slowly moving gamma chain variant was discovered in the cord blood of a baby of English-Vietnamese descent. The abnormality concerned the substitution of Gln residue in position 39(C5) of the A gamma chain by an Arg residue resulting in an -Arg-Arg- sequence at positions 39 and 40. The quantity of the A gamma chain variant was nearly 10% of the total Hb F with 15% of the Hb F having normal A gamma chains and 75% of Hb F having G gamma chains.

The percentages of Hb F and of G gamma and A gamma chains in the Hb F synthesized by reticulocytes and BFUe-derived colonies of patients with sickle cell anemia.

The synthesis of Hb F was studied in the BFUe-derived colonies of 20 SS patients after incubation with 35S methionine for 24 hours, 13 days after the start of the experiments. Similar analyses were made for isolated reticulocytes from 28 SS patients; these cells were incubated for 2 hours and occasionally for 24 hours. The G gamma and A gamma percentages were determined in these two Hb F preparations and in the Hb F of circulating red cells using two different HPL chromatographic procedures.