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Background and Aims Fifteen to twenty percent of alpha-1 anti-trypsin deficiency patients (A1ATD) have a severe liver outcome (portal hypertension - PHT) during childhood. Since they all share the same ZZ SERPINA1 genotype and that environmental factors such as alcohol cannot be advanced, the presence of modifier genes is now well-recognized. SNPs located on the SERPINA1 and MAN1B1 genes have already been tested in very few studies with contradictory or not replicated results. Methods Our genotype-phenotype correlation study, performed on 92 ZZ children, aimed at determining once and for all if SERPINA1 and MAN1B1 polymorphisms may be implied in the onset of PHT. To do so, we also performed for the first time a complete haplotype reconstruction for data analysis. Results The two genetic associations with severe liver disease that had been suspected previously (one SNP for SERPINA1 and another for MAN1B1) were not confirmed on our cohort. Moreover, the haplotype analysis identified only one major genetic background for the SERPINA1 Z-allele, allowing us to exclude the presence of a frequent modifier SNP within. For MAN1B1, four major haplotypes were identified but the prevalence of PHT did not significantly differ between them. Conclusion We conclude that genetic polymorphisms on these two genes probably do not influence the onset of severe liver disease in A1ATD. This article is protected by copyright. All rights reserved.

We developed a series of interrelated locus-specific databases to store all published and unpublished genetic variation related to these disorders, and then implemented microattribution to encourage submission of unpublished observations of genetic variation to these public repositories 1. A total of 1,941 unique genetic variants in 37 genes, encoding globins (HBA2, HBA1, HBG2, HBG1, HBD, HBB) and other erythroid proteins (ALOX5AP, AQP9, ARG2, ASS1, ATRX, BCL11A, CNTNAP2, CSNK2A1, EPAS1, ERCC2, FLT1, GATA1, GPM6B, HAO2, HBS1L, KDR, KL, KLF1, MAP2K1, MAP3K5, MAP3K7, MYB, NOS1, NOS2, NOS3, NOX3, NUP133, PDE7B, SMAD3, SMAD6, and TOX) are currently documented in these databases with reciprocal attribution of microcitations to data contributors. Our project provides the first example of implementing microattribution to incentivise submission of all known genetic variation in a defined system. It has demonstrably increased the reporting of human variants and now provides a comprehensive online resource for systematically describing human genetic variation in the globin genes and other genes contributing to hemoglobinopathies and thalassemias. The large repository of previously reported data, together with more recent data, acquired by microattribution, demonstrates how the comprehensive documentation of human variation will provide key insights into normal biological processes and how these are perturbed in human genetic disease. Using the microattribution process set out here, datasets which took decades to accumulate for the globin genes could be assembled rapidly for other genes and disease systems. The principles established here for the globin gene system will serve as a model for other systems and the analysis of other common and/or complex human genetic diseases.

We report two new variants of the δ-globin gene: Hb A(2)-Saint-Etienne [δ14(A11)Leu→Pro] and Hb A(2)-Marseille [δ22(B4)Ala→Lys]. The first variant has a low rate of expression, the second results from a double nucleotide mutation on the same codon.

To validate the recently proposed pediatric severity score (PSS) for sickle cell disease (SCD), we retrospectively assembled clinical data from a cohort of 122 patients with SCD (105 S/S or S/β(0) -thal. and 17 S/C) followed up for at least 2 years. Besides age and α- and β-globin genotypes, four new parameters were also tested against the PSS: duration of data assembly, neonatal screening, use of transcranial Doppler ultrasound to prevent vasculopathies and β-globin gene cluster haplotype. Once again, the PSS clearly differentiated patients by their β-globin genotype (P=0.004) but not by their age during data assembly (P=0.159). But, surprisingly, alpha-gene deletions were not associated with a lower PSS (P=0.604), possibly reflecting the opposite effects of α-thalassemia on global SCD severity. As for the newly tested parameters, the PSS appeared not to be influenced by the duration of data assembly (P=0.071) and neonatal screening (P=0.678) but rather by the introduction of transcranial Doppler ultrasound (P=0.006). Moreover, the Senegal haplotype at the homozygous state may be associated with a lower PSS. Methodologically, our data globally confirm the usefulness of the PSS to identify major etiological factors of SCD gravity. Nevertheless, the score is surely underestimated for patients who have been switched to a chronic therapy before the main SCD complications. Biologically, our study questions about the exact influence of α-thalassemia on global SCD severity.

Le diagnostic du deficit en α-1 antitrypsine (A1AT) repose sur la focalisation isoelectrique des proteines seriques et sur la mesure de la concentration serique. Cependant, la focalisation isoelectrique est techniquement delicate et une concentration fortement abaissee en A1AT sans bande anormale en focalisation isoelectrique ne permet pas de differencier un variant instable d’un variant dit « nul » (c’est-a-dire sans aucune expression phenotypique) a l’etat heterozygote. Dans la presente etude, nous avons compare les resultats du dosage, du phenotype et du genotype de l’A1AT chez 50 patients. Les alleles A1AT normaux (Pi*M1 a Pi*M4) ou deficitaires les plus courants (Pi*S et Pi*Z) ont ete parfaitement identifies au phenotypage. En revanche, le genotypage s’est avere necessaire pour caracteriser : (i) certains alleles A1AT plus rares (S-Munich, X-Christchurch) ; (ii) un allele nul et ; (iii) deux nouveaux alleles A1AT non encore decrits dans la litterature. En conclusion, meme si le genotypage A1AT n’est generalement pas necessaire, il est indispensable pour resoudre les cas complexes et pour obtenir des temoins valides pour la focalisation isoelectrique.

Background β-Globin haplotypes are important to predict the clinical development of patients suffering from sickle cell disease (SCD). Five main haplotypes (Benin, Bantu, Senegal, Cameroon and Arabic–Indian) are defined for βS chromosomes and their determination usually requires the genotyping by restriction fragment length polymorphism (RFLP) of six to eight single nucleotide polymorphisms (SNPs). However, RFLP is time-consuming and can lead to a misdiagnosis in case of a supplementary SNP on the restriction sequence. We propose a rapid β-globin haplotyping method using fluorescence resonance transfer (FRET) and high resolution melting (HRM) assays. Methods We have settled a fluorescence resonance energy transfer (FRET) assay for HincII e, XmnI, HindIII Gγ, HindIII Aγ, HincII δ and a high resolution melting (HRM) assay for HincII ψβ. These six SNPs are sufficient in most cases to determine the βS haplotype. Results Our methodology allowed us to successfully determine the β-globin haplotypes of 139 patients suffering from sickle cell disease. For some βS / β0-patients, a supplementary SNP has been identified on the HindIII Gγ restriction sequence leading to a false-negative RFLP result. Conclusion Combination of FRET and HRM assays is a rapid and reliable method for the β-globin gene cluster haplotyping.

We report the clinical and biochemical studies of a patient initially diagnosed with β-thalassemia intermedia (β-TI), which, with age, has progressed to a severe transfusion-dependent form. The patient is a compound heterozygote for the -30 (TA) β(+)-thalassemia (β(+)-thal) mutation and the rare δ(0)β(+)-Senegalese deletion. Many complications are reported as well as the specific treatments initiated.

The HbF level is a quantitative trait influenced by many loci inside or outside the beta-globin gene cluster. The aim of this study was to analyze in 57 beta-thalassemia intermedia patients with very various genotypes the effects on fetal hemoglobin levels of SNPs lying in three genes or chromosome regions which include the XmnI (G)gamma polymorphism at position -158 of the HBG2 promoter (rs7482144), two SNPs located in the BCL11A region (rs4671393 and rs11886868) and three SNPs located in the HBS1L-MYB region (rs28384513, rs9399137 and rs4895441). Our study shows a strong correlation between the XmnI (G)gamma polymorphism and the fetal hemoglobin expression in this patient population (p=0.002). Unfortunately, although recent studies clearly showed a role of SNPs in BCL11A and a HBS1L-MYB region on either clinical expression or fetal hemoglobin levels of beta-hemoglobinopathies such as sickle cell disease and beta-thalassemia, SNPs in BCL11A and the HBS1L-MYB region did not show statistically significant correlations with fetal hemoglobin levels. This suggests that the BCL11A and HBS1L-MYB loci have a minor effect on HbF level compared to the XmnI QTL in beta-thalassemia intermedia patients.

A chronic microcytosis and hypochromia without any iron deficiency were observed in an 11-year-old boy of French Caucasian origin. The same hematological findings were also found for his mother. No abnormal hemoglobin (Hb) was detected using isoelectric focusing, cation exchange liquid chromatography and reversed phase liquid chromatography of the globin chains but DNA sequencing revealed a CTGCCG transition at codon 106 (Leu--Pro) of the alpha1-globin gene in both of them. As the alpha/beta mRNA ratios, determined by reverse-transcriptase real-time quantitative polymerase chain reaction (PCR), are not concordant with an alpha-thalassemia (alpha-thal) state, we hypothesize that the underlying physiopathologic mechanism is an assembling defect of the Hb Charlieu molecule, rather than an instability of the alpha(Charlieu) mRNA. Moreover, genetic counseling and patient information are required in this family to prevent potentially severe alpha-thalassemias in following generations.

The diagnosis of the main hemoglobinopathies (HbS, HbC, HbE, heterozygous beta-thalassemia) is easy for laboratories using Hb electrophoresis and/or cation-exchange high performance liquid chromatography (CE-HPLC) methods. However, the diagnosis of alpha-thalassemias and of rare Hb variants is much more complex. Six French laboratories, forming together the "Pathologie hereditaire de l'erythrocyte" network, routinely practice the molecular diagnosis of hemoglobinopathies. These laboratories have shared their experiences to propose flowcharts for the phenotypical diagnosis and the molecular characterization of the main hereditary Hb pathologies. These flowcharts are applicable to any single patient with an adult erythropiesis (more than two-years-old), that is to say after the fetal to adult (gamma>beta) Hb commutation, when the HbF level is stabilized.

Objectives Nowadays, nearly 1000 hemoglobin (Hb) variants are known. The standard biochemical techniques used in Hb analysis are mainly: isoelectric focusing, cation-exchange liquid chromatography (LC) and reversed-phase LC. In addition to this approach, a protein analysis is achieved by mass spectrometry (MS) and additional DNA studies are performed. The aim of this review is to emphasize the significance of MS methods applied to Hb variants analysis. Results and perspectives To perform Hb studies, different MS techniques are currently used such as electrospray ionization (ESI), matrix-assisted laser desorption ionization (MALDI) and tandem mass spectrometry (MS/MS). As shown here, MS is an efficient tool for identification of all types of variants (substitution of a single amino acid residue, several substitutions in the same globin chain, insertions/deletions, fusion Hbs). The use of MS in neonatal screening of Hb variants is also presented. Conclusions MS is a powerful technique for Hb analysis. It appears as being an important additional method in the set of biochemical techniques.

We present here the case-report of a man with a severe G6PD deficiency revealed after the use of rasburicase (uricolytic drug) during a chemotherapy protocol. The genotypic analysis done to confirm the biochemical measurement revealed the 'Mediterranean mutation' at the hemizygous state (G6PD gene is located on chromosome X). Consequently to this diagnose, a search for G6PD deficiency has been performed (at the biochemical and genotypic levels) for the 9 children (7 daughters and 2 sons) of the proband. Surprisingly, one of his son was found to be hemizygous for the mediterranean mutation and one of his daughter appeared homozygous for this same mutation. This implies that the proband's wife (not studied) is certainly heterozygous for the mediterranean mutation, as it is very unlikely that this mutation had appeared de novo for two children of this couple.

Hemoglobinopathies are the most frequent genetic diseases in the world. Among them, the Hb S variant [beta6(A3)Glu-->Val], which, in the homozygous state, produces a severe disease known as sickle cell anemia with polymerization of Hb S inside red blood cells under hypoxic conditions. Additional mutations, in cis or in trans of the beta(S)-globin chain, may inhibit or enhance the polymerization process. We describe here a new hemoglobin (Hb) variant (Hb S-Clichy) which carries the beta(S)-globin chain and an additional mutation beta8(A5)Lys-->Thr. The variant was detected by routine electrophoretic techniques and cation exchange liquid chromatography (CE-LC). Globin chain separation by reversed phase LC (RP-LC) showed normal and abnormal beta chains, confirming that the additional abnormality was located in cis to Hb S. Electrospray ionization mass spectrometry (ESI-MS) gave a 57 Da mass decrease for the abnormal globin chain. The abnormal chain was isolated and submitted to trypsin digestion. Normal peptides betaT-1 and betaT-2 were not observed on the matrix-assisted laser desorption-time of flight (MALDI-TOF) mass spectrum but a new peptide betaT-1,2 was detected. Nano LC-ESI-MS/MS of the new peptide showed that the glutamic acid at codon 6 was replaced by a valine residue, and the lysine at codon 8 was replaced by a threonine residue, as confirmed by DNA sequencing. This example demonstrates that in a population where Hb S is present, every unidentified Hb needs to be clearly characterized to prevent major sickle cell syndromes. In addition, the identification of these variants must be considered in newborn screening for sickle cell disease, using either classical biochemical methods or MS techniques.

We present here five new hemoglobin (Hb) variants which have been identified during routine Hb analysis before their genotypic characterization. Four of these result from a classical missense mutation: Hb Canuts [α85(F6)Asp→His (α1)], Hb Ambroise Pare [α117(GH5)Phe→Ile (α2)], Hb Beaujolais [β84(EF8)Thr→Asn] and HbA2-North Africa [δ59(E3)Lys→Met]. The last one, Hb Monplaisir [β147 (Tyr-Lys-Leu-Ala-Phe-Phe-Leu-Leu-Ser-Asn-Phe-Tyr-158-COOH)], results from a frameshift mutation at the stop codon of the β-globin gene which leads to a modified C-terminal sequence in the β-globin chain. None of these variants seem to have a particular clinical expression in the heterozygous state. The circumstances of the discovery of these five new Hb variants emphasize the fact that an association of techniques is necessary for a complete screening of Hb variants during routine Hb analysis. Globin chain separation by reversed phase liquid chromatography (RP‐LC) appears to be the most relevant method.

Background: Hemoglobin (Hb) Groene Hart [α119 (H2)Pro→Ser (α1)], also known as Hb Bernalda, is a nondeletional α-thalassemic Hb variant that is frequent in southern Italy and North Africa. This variant is not supposed to be produced in the erythrocytes of carriers. The α-thalassemic behavior of this variant has been explained as an impaired interaction between the α-globin chain and the α-Hb–stabilizing protein.Methods: To separate globin chains, we developed a modified reversed-phase liquid chromatography (RPLC) procedure that uses acetonitrile–water solvents containing up to 3 mL/L trifluoroacetic acid. After RPLC, we characterized the isolated globin chains by electrospray ionization (ESI) mass spectrometry (MS) and analyzed their tryptic peptides with matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) MS and nano-LC–ESI–MS/MS.Results: RPLC detected an abnormal peak with a retention time substantially greater than that of the wild-type αA-globin chain. We identified this variant as Hb Groene Hart and found it in the hemolysates of 11 unrelated patients (1 homozygote, 9 heterozygotes, and 1 heterozygote associated with the −α3.7 deletion). These patients possessed abnormal hematologic features suggesting an α-thalassemia phenotype. Molecular modeling suggested that the increase in hydrophobicity was due to opening of the GH interhelical segment following replacement of amino acid residue 119 with a nonhelix breaker residue.Conclusions: This method allows the detection of Hb variants at low concentrations, and adjusting the composition of the organic solvents enables the method to identify Hb variants with large changes in hydrophobicity.

We report two new point mutations causing alpha-thalassemia (alpha-thal) that could not be characterized by conventional biochemical studies. The first mutation is a single base substitution at codon 123 of the alpha1-globin gene [alpha123(H6)Ala--Pro, GCCCCC (alpha1)] and leads to the substitution of a proline residue in the H helix. The resulting unstable hemoglobin (Hb) variant has been named Hb Voreppe. The second is a frameshift of the alpha2 gene due to a deletion (-C), either of the third base of codon 112 or of the first base of codon 113, that causes a premature stop codon at position 132.

The Hb Gerland [α55(E4)Val→Ala] mutation has been described in the α2-globin gene. We report here the same mutation in the paralogous α1-globin gene. This variant was found in a healthy 18-month-old boy of Chinese origin. Abnormal hemoglobin (Hb) fractions were visible on isoelectric focusing (IEF) and cation exchange high performance liquid chromatography (HPLC), with elution patterns differing from one system to another. Direct sequencing of the α-globin genes revealed a GTT>GCT (Val→Ala) transversion at codon 55 of the α1-globin gene. We propose to name the variant encoded by the α1-globin gene Hb Gerland [A1], and the variant that is encoded by the α2-globin gene Hb Gerland [A2].

Two new fetal hemoglobin (Hb F) variants affecting the Gγ chain are reported: Hb F-Saint-Etienne [Gγ79(EF3)Asp→His] and Hb F-Lyon [Gγ97(FG4)His→Arg]. These new Hb variants were found during a neonatal screening for hemoglobinopathies but characterized a few months later by our reference laboratory. The corresponding mutations are located on the external part of the Hb molecule and seem to be clinically silent.

The aim of the study was to examine the effects of endurance exercise on circulating vascular cell adhesion molecule-1 (sVCAM-1) and intercellular adhesion molecule-1 (sICAM-1) in sickle cell trait (SCT) athletes with or without alpha-thalassemia. Five athletes with SCT, 7 athletes with both SCT and alpha-thalassemia (SCTAT) and 8 control athletes (CONT) performed an incremental test on cycloergometer followed 72 hours later by a 60-min endurance exercise with a workload set at 70% P(peak) (peak power). We assessed levels of sICAM-1, sVCAM-1 and TNF-alpha at rest, immediately after endurance exercise and 1, 2, and 24 hours of recovery. Although, CONT and SCTAT groups exhibited similar basal plasma levels of adhesion molecules and TNF-alpha, SCT group had higher sVCAM-1 basal concentrations. No significant variation in sVCAM-1, sICAM-1 and TNF-alpha was measured following endurance exercise. Consequently, sVCAM-1 remained elevated in the SCT group after exercise and during the recovery period. In conclusion, our findings support the concept that SCT athletes might be at risk for microcirculatory disturbances, but these adhesive processes were not further impaired in response to endurance exercise. In addition, alpha-thalassemia co existing trait may be protective both at rest and after endurance exercise in SCT subjects.

We report here two new beta(0)-thalassemic mutations. In the first case, a deletion of two nucleotides (-CC) at codon 142 was found in a French Caucasian woman. In the second case, an insertion of a single nucleotide (+T) at codon 45 was found in a Turkish girl. In both cases, no dominant thalassemia-like phenotype was observed.

The aim of the study was to examine the effects of exercise on soluble vascular cell adhesion molecule-1 (sVCAM-1) and intercellular adhesion molecule-1 (sICAM-1) in sickle cell trait (SCT) athletes with or without α-thalassemia. Six athletes with SCT, seven athletes with both SCT and α-thalassemia (SCTAT), and seven control athletes (Cont) performed an incremental and maximal test on cycloergometer. Levels of sICAM-1 and sVCAM-1 were assessed at rest, immediately after the end of exercise, and 1, 2, and 24 h after exercise. Although Cont and SCTAT groups exhibited similar basal plasma levels of inflammatory and adhesion molecules, the SCT group had higher sVCAM-1 basal concentrations. Incremental exercise resulted in a significant increase of sVCAM-1 in all subjects, which remained elevated only in the SCT group during the recovery period. In conclusion, as sVCAM-1 increased with exercise and during the recovery period, our findings support the concept that SCT athletes might be at risk for microcirculatory disturbances and adhesive phenomena developing at rest and several hours after exercise. α-Thalassemia might be considered protective among exercising SCT subjects.

Background Alpha 1 antitrypsin (A1AT) deficiency (A1ATD) is potentially associated with a high degree of liver and/or lung disease. Apart from the most frequent deficiency alleles, Pi S and Pi Z, some A1AT alleles of clinical significance may be easily misdiagnosed. This is typically the case of the Pi Mmalton variant which shares the same ‘gain-of-function’ liver toxicity than Pi Z and the same ‘loss of function’ lung disease as well. Methods The biological diagnosis of A1ATD typically relies on a low serum concentration associated with an abnormal isoelectric focusing (IEF) pattern of migration. However, Sanger direct DNA sequencing may be required for deficiency alleles without biochemical expression (Null alleles) or for A1AT variants whose IEF profiles resemble the wild-type and sub-types M allele but with a low concentration. Results We report four cases of A1ATD involving the deficient Pi Mmalton allele with very different clinical expressions: (i) one Mmalton/Mmalton with liver fibrosis and cirrhosis, (ii) two Mmalton/Z with chronic pulmonary obstructive disease in one case and (iii) one M/Mmalton without liver or lung disease. In both cases, the correct diagnosis has necessitated a genetic analysis. Conclusions Our study provides another example of Pi Mmalton homozygosity associated with a severe liver disease that emphasizes the necessity of a not delayed diagnosis. The great clinical heterogeneity of the other genotypes (which is in agreement with the literature data) questions about the role of environmental and other modifier genes in the pathogenicity of A1ATD.

Resume Introduction Le deficit en alpha-1 antitrypsine (α1-AT), dont la forme moleculaire la plus frequente est l’homozygotie Z (SERPINA1 : c.1096 G>A ; Glu342Lys) se traduit par deux types d’atteintes cliniques : (i) une atteinte respiratoire avec emphyseme (touchant surtout l’adulte), en raison d’un deficit quantitatif en activite anti-elastasique au niveau pulmonaire ; (ii) une atteinte hepatique (touchant surtout l’enfant), liee a un defaut de repliement de la proteine PiZ qui s’accumule dans les hepatocytes sous forme de polymeres cytotoxiques. Etat des connaissances A ce jour, les facteurs cliniques et genetiques qui determinent chez l’enfant PiZ l’apparition des complications hepatiques du deficit en α1-AT (hypertension portale et fibrose) ne sont pas connus. Methodes La cohorte DEFI-ALPHA, creee en 2008, a pour but de recenser et de suivre prospectivement tous les enfants atteints d’un deficit en α1-AT dont l’inclusion s’est faite suite a un point d’appel hepatique. Le PHRC POLYGEN DEFI-ALPHA, debute en 2013, est venu completer le projet par la recherche de genes modificateurs du deficit en α1-AT selon deux approches : (i) strategie genes-candidats avec l’etude des genes SERPINA1, CFTR (gene de la mucoviscidose), MAN1B1 et SORL1 (genes impliques dans la degradation cellulaire des proteines mal repliees comme PiZ) ; (ii) strategie sequencage d’exome dans des familles presentant un enfant homozygote Z atteint et un frere ou une sœur egalement homozygote mais sans aucun signe hepatique. Resultats attendus Le parametre clinique que l’on cherche a expliquer est l’apparition de l’hypertension portale chez l’enfant homozygote Z. Dans le projet DEFI-ALPHA, trois criteres explicatifs seront testes : (i) l’âge d’inclusion dans la cohorte, (ii) le mode d’inclusion (ictere neonatal ou perturbation hepatique plus tardive) et (iii) la mise sous traitement ou non a l’acide ursodesoxycholique et, si oui, sa duree. Au niveau genetique, des polymorphismes sur SERPINA1 et MAN1B1 ont deja ete associes dans la litterature a des evolutions cliniques differentes du deficit en α1-AT mais de facon inconstante. Le but de notre etude sera donc de confirmer ou non cette association. Les genes CFTR et SORL1 n’ont eux jamais ete testes dans le cadre du deficit en α1-AT. Enfin, la strategie de sequencage d’exome pourrait permettre la decouverte de genes modificateurs pour l’heure insoupconnes.

We present here seven new hemoglobin (Hb) variants identified during routine Hb analysis. All of them are caused by a missense mutation except Hb Saint Chamond, which results from an in-frame deletion of the asparagine residue at β80. All these variants are clinically silent in the heterozygous state but two of them (Hb Cap d'Agde and Hb Dompierre) may be unstable, whereas Hb Nîmes could present a very slightly elevated oxygen affinity. These data are to be confirmed by appropriate biochemical tests.

The aim of this study was to test the association between hematological/genetic factors and cerebral vasculopathy in children with sickle cell anemia (SCA). A group with cerebral vasculopathy (VASC) was composed of children who had stroke (n = 6), silent infarct (n = 11), or an abnormal transcranial Doppler (n = 5). Eighty-four patients had neither positive history of stroke or silent infarct, nor abnormal transcranial Doppler (NORM group). An intermediate group (COND; n = 15) was composed of SCA children with a conditional transcranial Doppler. Biological analyses were performed on samples obtained at steady state and before the beginning of any chronic treatment. The comparisons of the three groups demonstrated a protective effect of α-thalassemia against cerebral vasculopathy through its effects on hemoglobin and reticulocyte levels. Moreover, we observed higher frequency of G6PD deficiency in the VASC group compared with the other groups. Our study confirms the key role of α-thalassemia and G6PD status in the pathophysiology of cerebral vasculopathy in SCA children.

Sickle cell trait (SCT) is a genetic disease affecting the synthesis of normal hemoglobin (Hb) marked by the heterozygous presence of HbA and HbS. It is thought that exercise tolerance and aerobic capacity could be limited in SCT carriers, but that the co-existence of alpha-thalassemia with SCT (SCTAT) could improve exercise response. To examine these issues, we compared the characteristics of VO2 kinetics during a constant heavy exercise among athletes carrying either the SCT (n = 6), the SCTAT (n = 9), or the normal Hb (control group; n = 10). After determination of maximal power output (Ppeak), all subjects underwent a constant heavy cycling exercise lasting 9 min at approximately 70 % Ppeak. Pulmonary VO2 and cardio-respiratory parameters were measured breath-by-breath and the VO2 response was modelled using non-linear regression techniques. The time constant of the VO2 primary component and oxygen deficit were not significantly different among the three groups. The VO2 slow component was 28 % and 33 % higher (p < 0.05) in SCT and SCTAT than in the control groups, respectively. Altogether, athletes with the SCT and the SCTAT had higher heart rate at the beginning (+ 5.2 %) and the end (+ 7.4 %) of the slow component compared to the control group (p < 0.05). These results suggest that SCT and SCTAT subjects are not limited during the first exercise minutes, but are prone to exercise intolerance and to lower aerobic capacity thereafter, due to a higher VO2 slow component, and that alpha-thalassemia does not improve exercise response. The finding of a higher slow component in SCT and SCTAT athletes was possibly due to the loss of O2 availability to muscles, additional fiber recruitment and/or higher cardiac load with time.

A new hemoglobin (Hb) variant in the heterozygous state, Hb Al-Hammadi Riyadh [codon 75 (GAC→GTC); α75(EF4)Asp→Val (α2)] corresponding to an A→T transversion on the second exon of the α2-globin gene, is described. The variant was characterized by DNA sequencing and mass spectrometry (MS). The variant was found during a routine Hb analysis for anemia in a 16-month-old boy who lived in Riyadh, Kingdom of Saudi Arabia.

A new mutation of the beta-globin gene initiation codon, ATG--AAG (Met--Tyr), is reported in a man originating from the southeast of France. Typical hematological findings of beta-thalassemia (thal) trait were found. We emphasize the importance of characterizing uncommon beta-thal mutations for genetic counseling.

A new G(gamma) hemoglobin (Hb) variant, Hb F-Bron [gamma20(B2)Val-->Ala] on the first exon of the G(gamma)-globin gene is described. The variant was characterized by DNA sequencing and mass spectrometry (MS). Hematological abnormalities included hypochromia and microcytosis and were probably caused by an interaction with an alpha-thalassemia (thal) (3.7 kb) deletion in the heterozygous state.

Two new hemoglobin (Hb) variants: Hb Brem-sur-Mer [codon 9 (TC T→TA T); β9(A6)Ser→Tyr] on the first exon of the β-globin gene and Hb Passy [codon 81 (T CC→C CC); α81(F2)Ser→Pro (α2)] on the second exon of the α2-globin gene, are described. The two variants were characterized by DNA sequencing and mass spectrometry (MS). Hematological abnormalities: microcytosis and hypochromia were found only in the carrier of Hb Passy. In the absence of an association with an α-thalassemic deletion or mutation, the mutation 81(F2)Pro could induce a possible α-thalassemia (thal).

Two new β‐globin chain variants: Hb Tripoli: codon 26, GAG→GCG [β26(B8)Glu→Ala] and Hb Tizi‐Ouzou: codon 29, GGC→AGC [β29(B11)Gly→Ser] are described on the first exon of the β‐globin gene. The two variants are characterized by DNA sequencing and mass spectrometry (MS). Hematological abnormalities were found in the two carriers. The presence of microcytosis and hypochromia is explained by an additional homozygous 3.7 kb α+ thalassemic deletion for the carrier of Hb Tizi‐Ouzou. Hb Tizi‐Ouzou showed a slight instability in vitro. The same hematological abnormalities associated with anemia are difficult to explain for Hb Tripoli's carrier in the absence of an α‐globin genes abnormality and could suggest a possible abnormal splicing.

The first new α chain variant here reported, Hb Die [α93(FG5)Val→Ala (α1)], was found during investigations of an anemia prior to surgery for correcting spina bifida. The patient was a 7‐year‐old g...

We report a new mutation on the α2-globin gene causing α(+)-thalassemia (α(+)-thal) with a deletion of a single nucleotide (T) at amino acid residue 43 [HBA2:c.130delT or HBA2:c.131delT]. This frameshift deletion gives rise to a premature termination codon at codon 47.

Hemoglobin Lyon-Bron was found in two members of a family of German ascent presenting with a moderate normocytic anemia. In this alpha2 globin variant, the N-terminal valine of the chain was replaced by an alanine. Electrospray mass spectrometry of the α chain showed that, as normally, the initiator methionine was cleaved during globin processing but that the Nα-terminal group was totally acetylated. This resulted in structural modifications of a region crucial for oxygen binding. As a consequence, hemoglobin Lyon-Bron displayed both a reduced chloride effect and a decreased oxygen affinity, this last point explaining the apparent anemia. Am. J. Hematol. 69:214–218, 2002. © 2002 Wiley-Liss, Inc.

We report a new β-globin chain variant: Hb Meylan [β73(E17)Asp → Phe; HBB: c.220G>T; c.221A>T]. The new variant results from a double nucleotide mutation at the same codon. The possible molecular mechanisms are discussed.

During routine hemoglobin (Hb) investigations for a possible hemoglobinopathy, performed on a 6-year-old boy suffering from mild microcytic anemia, an abnormal Hb was detected by cation exchange hi...

The Library of variants (LOV) v. 1.0 CD-Rom is a digital library of more than 200 typical cation-exchange HPLC graphs, for the phenotype determination of a haemoglobin disorder. These graphs, presented on a case-report form, have been obtained with the 4 Bio-Rad liquid chromatography devices available for haemoglobin analysis: D-10, Variant, Variant II and Variant nbs. In case of an atypical HPLC pattern obtained in clinical practice, this library will be of a potential useful help for the biologist to make a presumptive diagnosis of the type of haemoglobinopathy. Nevertheless, the definitive characterization will have to be made by molecular biology in a reference laboratory.

The decarboxylation of [1-13C]leucine by peroxyl radicals (ROO.) has been studied by using combined gas chromatography/isotope ratio mass spectrometry (GC/IRMS) to follow the production of 13CO2. Peroxyl radicals were obtained by thermal decomposition of a water soluble azo initiator, 2,2′-azobis(2-amidinopropane) dihydrochloride (AAPH). The decarboxylation rates measured by GC/IRMS were dependent on [1-13C]leucine and AAPH concentrations. The leucine partial order was found to be constant over a 60 min. period (0.6) but the AAPH partial order was found to be variable during the same period, from 1.0 (t = 0) to 0.50 (t = 60 min.). The identification of the products of reaction between leucine and peroxyl radicals requires the use of combined gas chromatography/mass spectrometry using the selected-ion monitoring mode. Methyl-3 butanoate was identified from comparison of its mass spectrum with that of a standard. © 1997 John Wiley & Sons, Ltd.

(1997). HB Zengcheng [β114(G16)LEU→MET] in a Cambodian Family. Hemoglobin: Vol. 21, No. 4, pp. 363-367.

We here report the phenotypes and genotypes of 63 patients of North African origin, carriers of Hb Groene Hart [Hb GH, α119(H2)Pro → Ser; HBA1: c.358C>T], an α+-thalassemia (α+-thal) hemoglobin (Hb) variant. Fifty patients were heterozygous, five were homozygous and eight also carried the common −α3.7 (rightward) deletion in compound heterozygosity. The expression of the αGH-globin chain is increased in the following order: heterozygous, compound heterozygous and homozygous. Parallel significant changes of mean corpuscular Hb (MCH) and mean corpuscular volume (MCV) were also observed. Our large cohort of Hb GH carriers could have been obtained by the systematic realization of globin chain separation by reversed phase liquid chromatography (RP-LC) in our routine Hb testing.

We present two case reports in which an HBD mutation is present with a rare α hemoglobinopathy that substantially complicates the associated phenotype. In the first case, a new δ-globin variant, Hb A2-Pierre-Benite [δ83(EF7)Gly→Arg; HBD: c.250G>C] is associated with Hb Groene Hart [α119(H2)Pro→Ser (α1); HBA1: c.358C>T], an α-thalassemic variant. In the second case, a δ(+)-thalassemic variant, δ4(A1)Thr→Ile; HBD: c.14C>T, is associated with a newly described deletion of the hypersensitive site 40 (HS-40) region on the α-globin gene cluster. In both patients, a δ-globin mutation was suspected because of an abnormally low Hb A2 level, whereas the α hemoglobinopathy was sought to explain the slight microcytosis and hypochromia presented by the probands.

Hemoglobin Debrousse (beta 96[FG3]Leu-->Pro) is a new unstable variant, with high oxygen affinity responsible, in the steady state, for an apparently well-compensated chronic hemolytic anemia. The functional properties of this variant are due to the replacement of a leucine residue which is involved in the hydrophobic environment of the proximal side of the heme. This electrophoretically neutral hemoglobin was found as a de novo case in a 6-year-old girl suffering from severe anemia with hemolysis and transient aplastic crisis, following infection by parvovirus B19.