A Woman with Missing Hb A2 Due to a Novel (εγ)δß0-Thalassemia and a Novel δ-Globin Variant Hb A2-Gebenstorf (HBD: c.209G>A).

A woman completely lacking Hb A2 on the high performance liquid chromatography (HPLC) analysis, presented with a novel deletional (εγ)δß0-thal and a δ-globin gene variant. This combination causes a ß-thalassemia (ß-thal) minor phenotype. The woman was referred by a hematologist due to abnormal blood counts. Multiplex ligation-dependent probe amplification (MLPA) and microarray analysis showed a heterozygous, 177 kb long deletion that removed the locus control region enhancer plus the ε, Gγ and Aγ genes. Additional sequencing revealed a novel variant HBD: c.209G>A, p.Gly70Asp in the heterozygous state, called Hb A2-Gebenstorf. The combination of the two variants explains the lack of Hb A2 in this woman.

Two novel α2 gene mutations causing altered amino acid sequences produce a mild (Hb Kinshasa, HBA2: c.428A > T) and severe (HBA2: c.342-345insCC) α-thalassemia phenotype.

We describe two novel α2 gene mutations that result in an altered amino acid sequence. In case 1, the α2 stop codon was mutated from TAA > TTA (HBA2: c.428A > T), resulting in an α2 protein chain extension of 31 amino acids. The new hemoglobin (Hb) variant was named Hb Kinshasa for the place of origin of the patient. This patient was also a carrier of Hb S (HBB: c.20A > T), which was expressed at reduced levels, but had an otherwise normal blood count. For cases 2 and 3, an α2 frameshift mutation caused a premature α2 protein chain termination at position 133 (HBA2: c.342-345insCC). The phenotype of this mutation seems to be rather severe as judged by the pronounced microcytosis and hypochromia observed in case 2. In addition, the father of this patient (case 3) also carried a ß(0)-thalassemia (ß(0)-thal) mutation (HBB: c.118C > T).

A new (G)γ-globin variant causing low oxygen affinity: Hb F-Brugine/Feldkirch [(G)γ105(G7)Leu→His; HBG2: c.317T>A].

In two unrelated families, several newborns developed cyanosis within the first days of life. For all of them, consecutive arterial blood gas analyses showed a right shift of the saturation curve, suggesting the presence of a hemoglobin (Hb) variant. A new (G)γ-globin variant was detected, namely (G)γ105(G7)Leu → His; HBG2: c.317T > A, that we named Hb F-Brugine/Feldkirch after the place of origin of the two families. This T to A conversion results in a leucine to histidine amino acid change at codon 105 of the (G)γ-globin gene and caused a Hb variant with lowered oxygen affinity. The γ to ß switch proceeded normally.

Neonatal cyanosis due to a new (G)γ-globin variant causing low oxygen affinity: Hb F-Sarajevo [(G)γ102(G4)Asn→Thr, AAC>ACC].

A baby girl, born at term, presented with severe cyanosis and received oxygen supplementation. Consecutive arterial blood gas analysis showed a pronounced right shift of the saturation curve, suggesting the presence of a hemoglobin (Hb) variant. A new (G)γ-globin variant was detected, namely HBG2:c.308G, which we have named Hb F-Sarajevo, the city from where the baby's parents originate. This A to C transversion exists in cis to the common (A)γ(T) and the resulting mutant Hb molecule exhibits very low oxygen affinity and cooperativity. Its analogue in the ß-globin gene is Hb Kansas [ß102(G4)Asn→Thr, AAC>ACC].

Comparison of two known chromosomal rearrangements in the 뫧-globin complex with identical DNA breakpoints but causing different Hb A(2) levels.

We report three cases with very heterogeneous Hb A(2) levels caused by known chromosomal rearrangements in the ß-globin locus. These rearrangements had their breakpoints at the same region in the δ gene, leading either to the Senegalese δ(0)ß(+)-thalassemia (δ(0)ß(+)-thal) deletion or to an insertion of a δ gene, known as Anti-Lepore. One patient showed, apart from drastically increased Hb A(2) values of 17.0%, inconspicuous hematological values. He had an Anti-Lepore mutation with three copies of the δ gene, thus explaining the high Hb A(2) level. Two other patients had Hb A(2) levels in the lower borderline range and increased Hb F levels. Molecular analysis showed the Senegalese δ(0)ß(+)-thal deletion. One of them presented with an additional mild ß-thal mutation leading to ß-thal intermedia. These cases illustrate that different gene rearrangements with the same breakpoints in the δ gene can lead to different levels of Hb A(2) depending on the remaining number of δ genes.

A rare case of coinheritance of Hemoglobin H disease and sickle cell trait combined with severe iron deficiency.

We present a case of a 40-year-old female from Turkey, who was referred to our outpatient clinic for an undetermined thalassemia and sickle cell trait. At first consultation hemoglobin was decreased (71 g/L) with microcytosis (MCV 55.1 fL), and hypochromia (MCHC 239 g/L). The patient had severe iron deficiency. Brilliant cresyl blue staining showed >50% of the erythrocytes with typical Hemoglobin H (HbH) inclusions. High-performance liquid chromatography (HPLC) revealed normal levels of HbA(2) and Hemoglobin F (HbF), and additionally a hemoglobin S (19%). Molecular diagnostics revealed the mutations α2 IVS-I donor site -5nt and a -- MED II deletion in the alpha gene complex and confirmed the heterozygote mutation of the beta-gene at codon 6 (HBB:c.20A>T; HbS). In conclusion, we present an extremely rare combination of HbH disease and sickle cell trait. This combination may explain the mild form of the HbH disease, with moderate anemia, splenomegaly but iron deficiency, rather than iron overload, as usually observed in HbH disease.

IL-12 initiates tumor rejection via lymphoid tissue-inducer cells bearing the natural cytotoxicity receptor NKp46.

The potent tumoricidal activity of interleukin 12 (IL-12) is thought to be mediated by the activation and polarization of natural killer (NK) cells and T helper type 1 (T(H)1) cells, respectively. By systematic analysis of the IL-12-induced immune response to subcutaneous melanoma (B16), we found that tumor suppression was mediated independently of T lymphocytes or NK cells. IL-12 initiated local antitumor immunity by stimulating a subset of NKp46(+) lymphoid tissue-inducer (LTi) cells dependent on the transcription factor RORγt. The presence of these NKp46(+) LTi cells induced upregulation of adhesion molecules in the tumor vasculature and resulted in more leukocyte invasion. Thus, this innate cell type is responsive to IL-12 and is a powerful mediator of tumor suppression.

Distinct expression patterns of the immunogenic differentiation antigen NY-BR-1 in normal breast, testis and their malignant counterparts.

NY-BR-1 is a differentiation antigen and a potential target for cancer immunotherapy. Its mRNA expression is restricted to breast, testis, prostate and breast cancer by RT-PCR. In this study, we correlated NY-BR-1 protein and mRNA expression on tissue microarrays of mammary, prostatic and testicular malignancies using immunohistochemistry and in situ hybridization with probes for exon 4-7 and 30-33. NY-BR-1 mRNA was confined to primary spermatocytes, suggesting a role in spermatogenesis. Exon 4-7 and 30-33 were equally expressed this cell type. However, NY-BR-1 was absent in all germ cell tumours analyzed (n = 475) and present in one of 56 (2%) prostate carcinomas. In breast, NY-BR-1 mRNA expression was detected in 307 of 442 (70%) primary carcinomas, with strong correlation to its protein expression (p < 0.0001). mRNA expression was significantly stronger and more frequently detected by the exon 30-33 probe than by the exon 4-7 probe (70% vs. 35%, p < 0.0001), indicating the presence of alternative splice variants that lack 5-prime sequences. A similar restricted mRNA pattern was also observed in the normal breast epithelium. NY-BR-1 protein and mRNA correlated significantly with estrogen receptor alpha (ER alpha) protein expression (p < 0.0001), with stronger association to NY-BR-1 mRNA than protein (odds ratio 7.7 compared to 4.6). We identified 4 estrogen response elements (ERE)-like sequences nearby the promoter region, suggesting that NY-BR-1 transcription might be controlled by ER alpha. Accordingly, analysis of matching pairs of primary tumors with their recurrences showed a marked decrease of NY-BR-1 expression in recurrences after tamoxifen treatment (p < 0.0001).

The transcriptional repressor Brinker antagonizes Wingless signaling.

In the embryonic midgut of Drosophila, Wingless (Wg) signaling elicits threshold-specific transcriptional response, that is, low-signaling levels activate target genes, whereas high-signaling levels repress them. Wg-mediated repression of the HOX gene Ultrabithorax (Ubx) is conferred by a response sequence within the Ubx B midgut enhancer, called WRS-R. It further depends on the Teashirt (Tsh) repressor, which acts through the WRS-R without binding to it. Here, we show that Wg-mediated repression of Ubx B depends on Brinker, which binds to the WRS-R. Furthermore, Brinker blocks transcriptional activation by ubiquitous Wg signaling. Brinker binds to Tsh in vitro, recruits Tsh to the WRS-R, and we find mutual physical interactions between Brinker, Tsh, and the corepressor dCtBP. This suggests that the three proteins may form a ternary repressor complex at the WRS-R to quench the activity of the nearby-bound dTCF/Armadillo transcription complex. Finally, brinker and tsh produce similar mutant phenotypes in the ventral epidermis, and double mutants mimic overactive Wg signaling in this tissue. This suggests that Brinker may have a widespread function in antagonizing Wg signaling.