Hb Extremadura or alpha 2 beta 2133 (H11)Val----Leu, a new mildly unstable hemoglobin in a Spanish female

Hb Hezhou [β64(E8)Gly→Ser; HBB: c.193G>A]: A Novel Variant on the β-Globin Gene

We report a novel mutation on the β-globin gene, Hb Hezhou [β64(E8)Gly→Ser; HBB: c.193G>A] that was detected in two unrelated Chinese individuals. Patient 1 also carried an α⁺-thalassemia (α⁺-thal) -α^4.2 (leftward) deletion, but hematological analyses showed no clinical consequences. Patient 2 was heterozygous for Hb Hezhou. Hemoglobin (Hb) analysis was performed using capillary electrophoresis (CE) and high performance liquid chromatography (HPLC). The Hb variant remained undetected using HPLC, while an additional peak was detected by CE. The finding of Hb Hezhou indicates that the possibilities of rare Hb variants should be alerted in the thalassemia screening program and precisely diagnosed depending on the Hb separation technique used.

Co-inheritance of Hb Hershey [beta70(E14) Ala-->Gly] and Hb La Pommeraie [beta133(H11)Val-->Met] in a Sicilian subject

OBJECTIVES

This report represents the first observation in Sicily of two rare beta-globin gene variants, Hb Hershey [beta70(E14) Ala-->Gly] and Hb La Pommeraie [beta133(H11)Val-->Met], found in a 35-year-old male patient from Messina, in the north-east of Sicily during population screening for hemoglobinopathies.

METHODS

The occurrence of the Hb variants was assessed by cation exchange chromatography while complete blood counts were obtained using automatic cell counters. Red cell lysates were analyzed by electrophoresis at alkaline and acid pH. Stability of hemoglobin was checked by the isopropanol precipitation test and by the heat tests while inclusion bodies and reticulocyte count were determined by incubation of blood samples with brilliant cresyl blue. Molecular analysis was performed by DNA sequencing of beta- and alpha-globin genes.

RESULTS

We observed an abnormally high performance liquid chromatography elution with a slight reduction in mean corpuscular volume and mean corpuscular haemoglobin parameters and mutations at codon 70 GCC-->GGC (Hb Hershey) and at codon 133 GTG-->ATG (Hb La Pommeraie) in beta-globin gene.

CONCLUSION

Family analysis of three generations demonstrated the presence of these two mutations in trans. So it was possible to describe the phenotypes of these variants in a heterozygous state and in double heterozygous state.

Hb Yaoundé [β134(H12)Val→Ala] in Association with Hb C [β6(A3)Glu→Lys] in a Caucasian Portuguese Family

Hb Yaoundé [beta134(H12)Val-->Ala] is a rare, silent and asymptomatic hemoglobin (Hb) variant. It was previously reported in a Black man from Cameroon, in association with Hb Kenitra [beta69(E13)Gly-->Arg], and was subsequently found and described as Hb Mataro in a sub-Saharan child. To date, Hb Yaoundé has not been described in Caucasian people and molecular studies have never been performed. Here we describe a three-generation Caucasian Portuguese family in whom Hb Yaoundé was found in association with Hb C [beta6(A3)Glu-->Lys] (in the proband) and in a heterozygous state (in the proband's mother). The Hb studies of the proband's hemolysate, performed by isoelectric focusing (IEF) and low-pressure cation exchange chromatography, only revealed an Hb variant identified as Hb C by comparison with a control. However, analysis performed by reversed-phase high-performance liquid chromatography (HPLC) showed two different beta chain variants and a complete absence of the normal beta chain. This uncommon Hb variant was identified as Hb Yaoundé by DNA sequencing analysis of the beta-globin gene (codon 134, GTG-->GCG). The beta-globin gene haplotypes were determined in all family members using polymerase chain reaction (PCR)-based methodology; Hb Yaoundé was found to be associated with the Mediterranean haplotype II. This study is the first description of Hb Yaoundé in Caucasian individuals, and its association with a Mediterranean haplotype supports the hypothesis of an independent genetic origin other than African.

Hb Ernz [beta123(H1)Thr-->Asn] and Hb Renert [beta133(H11)Val-->Ala]: two new neutral variants revealed by reversed phase high performance liquid chromatography analysis

Analysis of globin chains by reversed phase high performance liquid chromatography, used as an additional tool for characterizing hemoglobin variants, has led to the discovery of a new class of variants that display only differences in hydrophobicity. Two such variants are here described. Hb Ernz was found in a man of Italian origin who was polycythemic, and in two of his three daughters who were hematologically normal. Hb Renert, a slightly unstable variant, was found in a man from Cape Verde who also carried Hb S and presented with chronic hemolysis. The structural abnormalities were characterized by protein structure methods involving reversed phase high performance liquid chromatographic separations of globins and peptides, followed by mass spectrometry studies (electrospray, ion trap, tandem mass spectrometry).