A New α1-Globin Variant, Hb Ormylia [HBA1:c.63C > G; p.His21Gln]. Report of Eleven Cases in Northern Greece

The first identification of a novel α1-Globin variant, Hb Ormylia in 11 Greeks originating from a small village, Ormylia, Chalkidiki, Greece is reported. The new genetic variant leads to the production of a hemoglobin variant that can be identified and quantified by High-Performance Liquid Chromatography. Capillary and classic electrophoresis were not informative. Direct DNA sequencing revealed a new mutation C > G mutation at codon 21 of α1 gene (His > Gln). The new variant has been named Hb Ormylia and this is the first description of this genetic variant of α1 gene in the literature.

High-Oxygen-Affinity Hemoglobins-Case Series and Review of the Literature

Modifications of the hemoglobin (Hb) structure in regions involving the regulation of oxygen transport may lead to an increased oxygen affinity for the hemoglobin molecule and impaired oxygen delivery to the tissues. Herein, we present six patients with high-oxygen-affinity Hb variants, either in heterozygous form or in compound heterozygosity (such as heterozygosity for Hb Hiroshima, Köln, Crete, and compound heterozygosity Hb Crete with β or δβ thalassemia), in order to demonstrate the need for prompt and accurate diagnosis and enrich the limited literature due to the rarity of such cases. Hb Crete, Hb Hiroshima, and Hb Köln have distinct pathophysiologies and may result in different clinical phenotypes. In conclusion, high-oxygen-affinity hemoglobins are rare and inherited within a dominant autosomal manner, have various clinical presentations, and should always be suspected in patients with erythrocytosis. Their management (as phlebotomy or low-dose aspirin) should be based on an individualized assessment of the risk of complications, the medical history, concomitant symptoms, and quality of life.

Rare Pathogenic β0-Thalassemia Mutation, Codon 7 (GAG>TAG) (HBB: c.22G>T). Report of the First Two Cases in Albanian Immigrants of Northern Greece

We report the hematological data of the codon 7 (GAG>TAG (HBB: c.22G>T) mutation for the first time in two Albanian individuals from the region of Elbasan, who underwent genetic testing due to prenatal counseling and diagnosis for β-thalassemia major (β-TM) anemia. The phenotype was compatible with a typical β⁰-thalassemia (β⁰-thal) carrier but the hematological findings of the mutation has not been previously reported. The mutation involves the conversion of codon 7 GAG (Glu) into a translation termination codon (TAG), involving the replacement of guanine by thymine so that no β chains are produced.

Fetal heterozygosity for both Hb G-Hsi-Tsou and beta thalassemia: A case report

Introduction

This case report describes a fetus with compound heterozygosity for Hb G-Hsi-Tsou and beta thalassemia, diagnosed in a healthy pregnancy. To the best of our knowledge, this is the first documented case of compound heterozygosity and the woman is the second known case of heterozygosity for Hb G-Hsi-Tsou.

Case presentation

A 34-year-old woman during her first pregnancy underwent hemoglobin electrophoresis which revealed heterozygosity for Hb G-Hsi-Tsou. Hemoglobin G-Hsi-Tsou constitutes a hemoglobin variant with a structural abnormality of the beta chain, first described in 1972, but since then no other cases have been reported. After finding out that her husband was heterozygous for beta thalassemia, chorionic villus sampling revealed the embryo's heterozygosity for both Hb G-Hsi-Tsou and beta thalassemia. Due to lack of scientific data, the couple decided to end the pregnancy.

Conclusion

It was not possible to determine whether the fetus would present serious deficiencies in hematopoiesis, as Hb G-Hsi-Tsou is a variant which is not yet fully understood. What made this case even more complex was the simultaneous presence of the beta thalassemia allele.

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Electrophoresis can be used to reveal heterozygosity for Hb G-Hsi-Tsou.

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Chorionic villus sampling was performed in the case described, revealing heterozygosity for both Hb G-Hsi-Tsou and beta thalassemia.

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Hb G-Hsi-Tsou occurs due to a substitution of aspartic acid for glycine at position 79, creating an anomalous βT9 peptide.

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It was not possible to determine whether the fetus would present serious deficiencies in hematopoiesis.

Compound Heterozygosity for Hb Adana (HBA2: c.179G>A) and the -α3.7/αα Thalassemia Deletion in Greece: Clinical Phenotype and Genetic Counseling

Hb Adana (HBA2: c.179G>A) is found worldwide but is extremely rare and carriers are asymptomatic, with red cell indices similar to α⁺-thalassemia (α⁺-thal) carriers. First line screening tests are unable to detect the unstable hemoglobin (Hb). Coinheritance with the α-thal (-α^3.7) deletion is herein presented and the challenges involving genetic counseling of couples carrying the mutations are discussed.

Visfatin, TNF-alpha and IL-6 mRNA expression is increased in mononuclear cells from type 2 diabetic women

Visfatin, is a new adipokine, highly expressed in the visceral fat of both mice and humans. To examine whether visfatin is expressed in human peripheral monocyte-enriched mononuclear cells and whether its expression is altered in type 2 diabetes (DM2), we compared 24 DM2 women [17 overweight (BMI >25) and 7 lean (BMI<25)] to 26 healthy women (14 overweight and 12 lean), all premenopausal. Relative visfatin mRNA levels were significantly higher (approximately 3-fold) in DM2 compared to healthy control women (p<0.02), independently of the presence of overweight/obesity. Mononuclear TNF-alpha and IL-6 mRNA expression was also elevated in DM2 compared to control women (p=0.001 and p=0.004, respectively), an increase observed in both lean and overweight DM2 women. By contrast, circulating visfatin, TNF-alpha, and IL-6 levels showed no difference between DM2 and control women, while adiponectin plasma levels were significantly decreased in the DM2 women (p<0.001). Circulating visfatin and TNF-alpha levels did not differ either between the lean and the overweight subgroups of DM2 and control women, while IL-6 plasma levels were significantly higher in both overweight subgroups compared to their lean counterparts. In conclusion, visfatin, TNF-alpha, and IL-6 mRNA expressions are increased in peripheral mononuclear-monocytic cells from women with type 2 diabetes, independent of their BMI, which may enhance the effects of their adipose-derived levels and may contribute to the increased insulin resistance and atherogenic risk of these patients.

Involvement of cell surface HSP90 in cell migration reveals a novel role in the developing nervous system

Heat shock protein HSP90 plays important roles in cellular regulation, primarily as a chaperone for a number of key intracellular proteins. We report here that the two HSP90 isoforms, alpha and beta, also localize on the surface of cells in the nervous system and are involved in their migration. A 94-kDa surface antigen, the 4C5 antigen, which was previously shown to be involved in migration processes during development of the nervous system, is shown to be identical to HSP90alpha using mass spectrometry analysis. This identity is further confirmed by immunoprecipitation experiments and by induction of 4C5 antigen expression in heat shock-treated embryonic rat brain cultures. Moreover, immunocytochemistry on live cerebellar rat cells reveals cell surface localization of both HSP90alpha and -beta. Cell migration from cerebellar and sciatic nerve explants is inhibited by anti-HSP90alpha and anti-HSP90beta antibodies, similarly to the inhibition observed with monoclonal antibody 4C5. Moreover, immunostaining with rhodamine-phalloidin of migrating Schwann cells cultured in the presence of antibodies against both alpha and beta isoforms of HSP90 reveals that HSP90 activity is associated with actin cytoskeletal organization, necessary for lamellipodia formation.

The 4C5 antigen is associated with Schwann cell migration during development and regeneration of the rat peripheral nervous system

The monoclonal antibody 4C5 recognizes a cell surface antigen of the developing central nervous system (CNS) and peripheral nervous system (PNS). In vitro antibody perturbation experiments have shown that the 4C5 antigen is involved in horizontal and vertical migration processes of granule cells during development of the rodent cerebellum. Moreover, results concerning the cellular localization and temporal expression of the 4C5 antigen during development and after injury of the rat sciatic nerve suggested that it may participate in Schwann cell migrations that occur during the above processes. To test this possibility, we examined the effects of our function-blocking antibody on Schwann cell migration in three in vitro bioassays: in tissue cultures from developing sciatic nerve, in dorsal root ganglion cultures on cryostat sections of normal or denervated adult sciatic nerve, and in pure Schwann cell cultures. The results showed that the presence of monoclonal antibody 4C5 in all the above culture systems strongly inhibited Schwann cell migration, indicating that the 4C5 antigen participates in migration processes that take place during development and regeneration of the peripheral nervous system. Moreover, staining of migrating Schwann cells in the presence of monoclonal antibody 4C5 with rhodamine-phalloidin showed that 4C5 antigen activity is associated with actin cytoskeletal organization of these cells, and more specifically with lamellipodia formation.

Migration behavior of rodent granule neurons in the presence of antibody to the 4C5 antigen

We have reported the production of monoclonal antibody 4C5, which recognizes a cell surface antigen, the 4C5 antigen, involved in granule cell migration processes. In the present study, we investigated in a more precise manner the role of the 4C5 antigen in the different types of granule cell migrations that take place during cerebellar development. When cerebellar explant cultures derived from 10-day-old rats were performed for 2 days in the presence of monoclonal antibody 4C5, vertical granule cell migration, occurring in the presence of glia, was not significantly inhibited. In contrast, when monoclonal antibody 4C5 was included in the medium of microexplant cultures derived from 4-day-old mice and maintained for 4 days in vitro, granule cell migrations that occurred both parallel and perpendicular to the neurite bundles that were free of glia were inhibited. Moreover, a stronger inhibitory effect of the antibody was observed on migration perpendicular to the neurite bundles compared with the parallel type of migration. Our results indicate that the 4C5 antigen differentially affects the different developmental stages and types of granule cell migration during rodent cerebellar development.

Expression of the 4C5 antigen during development and after injury of the rat sciatic nerve

We have previously reported the production of monoclonal antibody 4C5 that recognizes a cell surface neuron specific antigen, the 4C5 antigen (Thomaidou and Patsavoudi: Neuroscience 53:813-827, 1993). Antibody perturbation experiments have suggested that the 4C5 antigen is involved in granule cell migration processes in vitro (Thomaidou et al: J Neurochem 64:1937-1944, 1995). In the present study, we have used monoclonal antibody 4C5 to investigate the cellular distribution and the expression of the corresponding antigen during development, and after injury of the rat sciatic nerve. Immunocytochemistry revealed presence of the protein both in myelin and non-myelin forming Schwann cells. Western blot analysis showed that monoclonal antibody 4C5 recognizes the same 94 kdalton polypeptide in the sciatic nerve as in the brain. Immunocytochemical analysis revealed an age-dependent decline of the 4C5 antigen expression. Moreover, following adult sciatic nerve crush, 4C5 immunoreactivity becomes intense in Schwann cells of the distal segment, as early as 4 days after injury and remains at relatively high levels up to 2 weeks after the crush. By the 3rd week, 4C5 immunoreactivity is greatly reduced, and by the 4th week it is hardly detectable. Our results concerning the cellular localization and temporal expression of the 4C5 antigen during development and after injury of the rat sciatic nerve, suggest that it may participate in Schwann cell migrations that occur during such processes.