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Background Defective synthesis of the α-globin chain due to mutations in the alpha-globin genes and/or its regulatory elements leads to alpha thalassaemia syndrome. Complete deletion of the 4 alpha-globin genes results in the most severe phenotype known as haemoglobin Bart’s, which leads to intrauterine death. The presence of one functional alpha gene is associated with haemoglobin H disease, characterised by non-transfusion-dependent thalassaemia phenotype, while silent and carrier traits are mostly asymptomatic. Main body Clinical manifestations of non-deletional in alpha thalassaemia are varied and have more severe phenotype compared to deletional forms of alpha thalassaemia. Literature for the molecular mechanisms of common non-deletional alpha thalassaemia including therapeutic measures that are necessarily needed for the understanding of these disorders is still in demand. This manuscript would contribute to the better knowledge of how defective production of the α-globin chains due to mutations on the alpha-globin genes and/or the regulatory elements leads to alpha thalassaemia syndrome. Conclusion Since many molecular markers are associated with the globin gene expression and switching over during the developmental stages, there is a need for increased awareness, new-born and prenatal screening program, especially for countries with high migration impact, and for improving the monitoring of patients with α-thalassaemia.

Trisomy 21 is chromosomal abnormality that occurs as a result of triplication of human chromosome 21 (Hsa21), a condition also known as Down syndrome (DS). Beside the intellectual disability and systems anomalies, motor dysfunction due to hypotonia has also been characterised in individuals with DS and yet, its aetiology remains unclear. Ts1Cje, a mouse model for DS, has a partial trisomy (Mmu16) homology to Hsa21, is widely used for DS research. This study investigated the morphological changes and degree of myelination in sciatic nerves of the Ts1Cje mice using both light and transmission electron microscopes processed images. The result showed no morphological difference in the sciatic nerve between the Ts1Cje and WT mice. The g ratio of the Ts1Cje mice was significantly (P

Objective The Filipino β°-deletion has been reported as a unique mutation in East Malaysia with a severe phenotype due to the complete absence of β-globin chain synthesis. In this study, the haplotype patterns of the β-globin gene cluster were used to relate the human genetic variation to this specific β-thalassaemia mutation. Methods The 376 study subjects included 219 β-thalassaemia major (β-TM) patients with homozygous Filipino β°-deletion and 157 carriers with heterozygous Filipino β°-deletion from 10 government hospitals in different regions of Sabah. Genomic DNA was isolated from whole blood using silica membrane based DNA purification protocol. Polymerase chain reaction restriction fragment length polymorphism analysis (PCR-RFLP) was conducted on five markers within the β-globin gene cluster to construct the haplotype patterns. Results Four haplotypes (Haplotype I-IV) were identified with Haplotype I as the predominant haplotype with the highest frequency of 0.98, followed by Haplotype II, III and Haplotype IV with 0.02. Haplotype I was strongly linked with the Filipino β°-deletion among the indigenous population. Conclusion Haplotype I as the predominant haplotype suggests the patients with the Filipino β°-deletion in Sabah have a similar origin.

Introduction: Alpha thalassaemia is a highly prevalent disease globally and is a well-known public health problem in Malaysia. The deletional forms of the mutation are the most common forms found in alpha thalassaemia. The three most common deletional alpha thalassaemia found in this region include --SEA deletion, -α3.7 rightward and -α4.2 leftward deletions. The prevalence rate of triplication alpha cases such as αααanti3.7 and αααanti4.2 is not known in Malaysia although it plays a role in exacerbating the clinical phenotypes in beta thalassaemia carriers. Recently, there have been more reported cases of rare alpha thalassaemia mutations due to the advancement of molecular techniques involved in thalassaemia detections. Therefore, it is essential to develop a new method which allows the detection of different alpha thalassaemia mutations including the rare ones simultaneously and accurately. Methods: The purpose of this study was to design an assay for the detection of triplications, common and rare deletional alpha thalassaemia using droplet digital PCR (ddPCR). Results: This is a quantitative detection method to measure the changes of copy number which can detect deletions, duplications and triplications of the alpha globin gene simultaneously. Conclusion: In conclusion, ddPCR is an alternative method for rapid detection of alpha thalassaemia variants in Malaysia.

The diverse clinical phenotype of hemoglobin E (HbE)/β-thalassemia has not only confounded clinicians in matters of patient management but has also led scientists to investigate the complex mechanisms involved in maintaining the delicate red cell environment where, even with apparent similarities of α- and β-globin genotypes, the phenotype tells a different story. The BTB and CNC homology 1 (BACH1) protein is known to regulate α- and β-globin gene transcriptions during the terminal differentiation of erythroid cells. With the mutations involved in HbE/β-thalassemia disorder, we studied the role of BACH1 in compensating for the globin chain imbalance, albeit for fine-tuning purposes.A total of 47 HbE/β-thalassemia samples were analyzed using real-time quantitative polymerase chain reaction and correlated with age, sex, red blood cell parameters, globin gene expressions, and some clinical data.The BACH1 expression among the β-thalassemia intermedia patients varied by up to 2-log differences and was positively correlated to age; α-, β-, and γ-globin gene expression level; and heme oxygenase 1 protein. BACH1 was also negatively correlated to reticulocyte level and had a significant correlation with splenectomy.This study indicates that the expression of BACH1 could be elevated as a compensatory mechanism to decrease the globin chain imbalance as well as to reduce the oxidative stress found in HbE/β-thalassemia.Amaç: Hemoglobin E (HbE)/β-talaseminin çeşitli klinik fenotipleri klinisyenlerin hasta yönetimi esnasında zihinlerini karıştırmakla kalmamış, α- ve β-globin genotiplerinde bariz benzerlikler varken fenotiplerde farklılıklar bulunduğundan bilim insanlarının hassas eritrosit çevrenin muhafaza edilmesinde yer alan karmaşık mekanizmaları incelemelerine de ön ayak olmuştur. BTB ve CNC homoloji 1 (BACH1) proteininin eritroid hücrelerin son farklılaşması sırasında α- and β-globin gen transkripsiyonlarını ayarladığı bilinmektedir. HbE/β-talasemi hastalığındaki mutasyonlar ile her ne kadar ince ayar amaçlı ise de BACH1’in globin zincir dengesizliğini kompanse etmedeki rolünü inceledik. Gereç ve Yöntemler: Toplam 47 HbE/β-talasemi örneği gerçek zamanlı kantitatif polimeraz zincir reaksiyonu ile incelendi ve yaş, cinsiyet, eritrosit değişkenleri, globin gen sunumları ve bazı klinik veriler ile korele edildi. Bulgular: β-talasemi intermedia hastalarındaki BACH1 sunumu 2-log’a kadar farklılık göstermekteydi ve yaş; α-, β- ve γ-globin gen sunum düzeyleri; ve hem oksijenaz 1 proteini ile pozitif korelasyonu vardı. Ayrıca BACH1’in retikülosit düzeyi ile negatif korelasyonu vardı ve splenektomi ile anlamlı korelasyonu bulunmaktaydı. Sonuç: Bu çalışma hem HbE/β-talasemide bulunan oksidatif stresi hem de globin zincir dengesizliğini azaltmak için BACH1 sunumunun kompansasyon mekanizması olarak artabileceğini göstermiştir.

Background: Down syndrome (DS) is a genetic disorder caused by presence of extra copy of human chromosome 21. It is characterised by several clinical phenotypes. Motor dysfunction due to hypotonia is commonly seen in individuals with DS and its etiology is yet unknown. Ts1Cje, which has a partial trisomy (Mmu16) homologous to Hsa21, is well reported to exhibit various typical neuropathological features seen in individuals with DS. This study investigated the role of skeletal muscles and peripheral nerve defects in contributing to muscle weakness in Ts1Cje mice. Results: Assessment of the motor performance showed that, the forelimb grip strength was significantly (P

Fetal spleen is a major hematopoietic site prior to initiation of bone marrow hematopoiesis. Morphologic analysis suggested erythropoietic activity in fetal spleen, but it remained unclear how erythropoiesis was regulated. To address this question, we performed flow cytometric analysis and observed that the number of spleen erythroid cells increased 18.6-fold from 16.5 to 19.5 days post-coitum (dpc). Among erythropoietic cytokines, SCF and IGF-1 were primarily expressed in hematopoietic, endothelial and mesenchymal-like fetal spleen cells. Cultures treated with SCF and/or IGF-1R inhibitors showed significantly decreased CD45−c-Kit−CD71+/−Ter119+ erythroid cells and downregulated Gata1, Klf1 and β-major globin expression. Administration of these inhibitors to pregnant mice significantly decreased the number of CD45−c-Kit−CD71+/−Ter119+ cells and downregulated β-major globin gene expression in embryos derived from these mice. We conclude that fetal spleen is a major erythropoietic site where endothelial and mesenchymal-like cells primarily accelerate erythropoietic activity through SCF and IGF-1 secretion.

Fetal hemoglobin (HbF) is the predominant hemoglobin in red cells during fetal life. Just after birth, the level of HbF decreases gradually to1%, and is replaced mainly by adult hemoglobin (HbA) (∼ 97%). However, higher HbF levels could be associated with HbE/β-thalassemia, a complex thalassemia intermedia with a diverse clinical severity ranging from mild-to-severe anemia. This study investigates the correlation of HbF level with the clinical and laboratory data of HbE/β-thalassemia individuals.Peripheral blood samples from 30 HbE/β-thalassemia subjects were subjected to a full blood count, genomic as well as quantitative real-time polymerase chain reaction gene expression studies. Statistical analyses were performed using SPSS 17.0.HbF levels were influenced by age, mean cell volume (MCV), mean cell hemoglobin (MCH), HbA, β-globin, and α/β-globin expressions.HbF production is affected by the α/β-globin chain imbalance due to the lack of β-globin gene expression as well as inversely correlates to the amount of functional hemoglobin available in the cells.

Current viral gene delivery vectors for gene therapy are inefficient due to short-lived transgene expression attributed to the cytosine-phosphate-guanine (CpG) motifs in the transgene. Here we assessed the effects of CpG motif reduction in lentiviral (LV) gene delivery context on the level and duration of reporter gene expression in Chinese Hamster Ovary (CHO) cells, Human Immortalized Myelogenous Leukemia (K562) cells and hematopoietic stem cells (HSCs). The cells were transduced with LV carrying Zero-CpG green fluorescent protein (ZGFP) reporter gene, LV/CMV/ZGFP. The GFP expression was compared to its non CpG-depleted GFP reporter gene LV (LV/CMV/GFP) counterpart. The LV/CMV/ZGFP exhibited prolonged transgene expression in CHO cells and HSCs up to 10 days and 14 days, in the respective cells. This effect was not seen in the transduced K562 cells, which may be due to the DNA hypomethylation status of the cancer cell line. Transgene copy number analysis verified that the GFP expression was not from pseudo-transduction and the transgene remained in the genome of the cells throughout the period of the study. The modest positive effects from the LV/CMV/ZGFP suggest that the reduction of CpG in the LV construct was not substantial to generate higher and more prolonged transgene expression.

Beta-thalassemia is one of the most prevalent inherited diseases and a public health problem in Malaysia. Malaysia is geographically divided into West and East Malaysia. In Sabah, a state in East Malaysia, there are over 1000 estimated cases of β-thalassemia major patients. Accurate population frequency data of the molecular basis of β-thalassemia major are needed for planning its control in the high-risk population of Sabah. Characterization of β-globin gene defects was done in 252 transfusion dependent β-thalassemia patients incorporating few PCR techniques. The study demonstrates that β-thalassemia mutations inherited are ethnically dependent. It is important to note that 86.9% of transfusion-dependent β-thalassemia major patients in Sabah were of the indigenous population and homozygous for a single mutation. The Filipino β(0)-deletion was a unique mutation found in the indigenous population of Sabah. Mutations common in West Malaysia were found in 11 (4.3%) patients. Four rare mutations (Hb Monroe, CD 8/9, CD 123/124/125 and IVS I-2) were also found. This study is informative on the population genetics of β-thalassemia major in Sabah.

Assembly of complex vascular networks occurs in numerous biological systems through morphogenetic processes such as vasculogenesis, angiogenesis and vascular remodeling. Pluripotent stem cells such as embryonic stem (ES) and induced pluripotent stem (iPS) cells can differentiate into any cell type, including endothelial cells (ECs), and have been extensively used as in vitro models to analyze molecular mechanisms underlying EC generation and differentiation. The emergence of these promising new approaches suggests that ECs could be used in clinical therapy. Much evidence suggests that ES/iPS cell differentiation into ECs in vitro mimics the in vivo vascular morphogenic process. Through sequential steps of maturation, ECs derived from ES/iPS cells can be further differentiated into arterial, venous, capillary and lymphatic ECs, as well as smooth muscle cells. Here, we review EC development from ES/iPS cells with special attention to molecular pathways functioning in EC specification.

Summary Aims Classical carriers of β 0 -thalassaemia are identified by a raised HbA 2 level. Earlier studies indicated that the Filipino β 0 -deletion has high raised HbA 2 levels. The introduction of automated high performance liquid chromatography (HPLC) for thalassaemia screening is an important advance in technology for haematology laboratories. The BioRad Variant II Hb analyser is a common instrument used to quantify HbA 2 levels in thalassaemia screening. This study aimed to determine HbA 2 levels in carriers of Filipino β 0 -mutation using the BioRad Variant II Hb analyser. Methods The Filipino β 0 -deletion was identified using gap-polymerase chain reaction (PCR) in the parents of transfusion dependent β 0 -thalassaemia patients who were homozygous for the Filipino β 0 -deletion in the indigenous population of Sabah, Malaysia. Hb subtypes were quantified on the BioRad Variant II Hb analyser. Concurrent α-thalassaemia was identified by multiplex gap-PCR for deletions and amplification refractory mutation system (ARMS)-PCR for non-deletional mutations. Results The mean HbA 2 level for Filipino β 0 -thalassaemia trait was 5.9 ± 0.47 and with coinheritance of α-thalassaemia was 6.3 ± 0.44 (-α 3.7 heterozygous) and 6.7 ± 0.36 (-α 37 homozygous). The HbA 2 levels were all >4% in keeping with the findings of classical β-thalassaemia trait and significantly higher than levels seen in non-deletional forms of β-thalassaemia. Conclusion The HbA 2 level measured on the BioRad Variant II Hb analyser was lower than the level in the first description of the Filipino β 0 -thalassaemia. β-thalassaemia trait with coinheritance of α-thalassaemia (-α 3.7 ) is associated with significantly higher HbA 2 level.

Hemoglobin (Hb) Adana [HBA2: c179G>A (or HBA1); p.Gly60Asp] is a non-deletional α-thalassemia variant found in Malaysia. An improvement in the molecular techniques in recent years has made identification of Hb Adana much easier. For this study, a total of 26 Hb Adana α-thalassemia intermedia and 10 Hb Adana trait blood samples were collected from patients. Common deletional and non-deletional α-thalassemia genotypes were determined using multiplex gap polymerase chain reaction (PCR) and multiplex ARMS PCR techniques. Identification of the Hb Adana location on the α-globin gene was carried out using genomic sequencing and the location of the mutation was confirmed via restriction fragment length polymorphism-PCR. Among the 36 samples, 24 (66.7%) had the -α(3.7)/α(Cd59)α mutation, while the -α(3.7)/α(Cd59)α mutation accounted for 2 samples (5.6%) and the remaining 10 (27.8%) samples were α/α(Cd59)α. All 36 samples were found to have the Hb Adana mutation on the α2-globin gene. The position of the α-globin gene mutation found in our cases was similar to that reported in Indonesia (16%) but not to that in Turkey (0.6%). Our results showed that the Hb Adana mutation was preferentially present in the α2-globin genes in Malays compared to the other ethnicities in Malaysia. Thus, the Malays might have similar ancestry based on the similarities in the Hb Adana position.

Ferritin plays an important role in iron detoxification and iron storage by converting soluble iron(II) to insoluble iron(III) inside the protein cage. Mechanism of in vitro ferritin iron release occurs more readily under reducing conditions, whereby reducing agents may enter into the ferritin cage through the protein pores to convert insoluble iron(III) into soluble iron(II), after accepting an electron from reducing agents. The soluble iron(II) then liberates outside the protein cage and forms coloured and stable complexes in the presence of chromophore, an iron(II) chelating agent, to be quantified by spectrophotometry. However, iron(II) is readily converted back to iron(III) in the presence of oxygen. Thus, oxygen scavenger compounds were used to remove any dissolved oxygen. Studies suggested that low concentration of chaotropic agents regulate the protein pore opening and result in protein unfolding that is therefore accessible by reducing agents more effectively. According to in vivo studies, iron exit from ferritin for recycling or meeting the cell's need via lysosomal and/or proteasomal pathways. We designed an assay to determine the total iron available inside the ferritin by first using the commercially available iron(II) or iron(III) compounds as a substrate to optimize the concentration of reactants involved. Apart from chromophore and reducing agents, oxygen scavenger compounds, chaotropic agents and enzymes were added in order to induce ferritin iron release effectively. Linear calibration curve of the iron(II)-chromophore complex were obtained and was used as a reference to correlate absorbance readings to concentration of iron level. Reducing agents was able to reduce the iron(III) to iron(II) and oxygen scavenger A seems to be more effective in removing any dissolved oxygen to avoid oxidation of both the reducing agents and iron(III). Taken altogether, this experiment setup will be beneficial for the improvement of efficiency in quantifying the total iron level inside the ferritin.

In our bloodstream, there are plenty of red blood cells (RBC), which function as an important oxygen carrier in our bodies. Each RBC consists of millions of haemoglobin (Hb), which is made up from globin and iron. If any deficiency/malfunction of any globin, it will lead to anaemia as indicated in low Hb level while iron deficiency anaemia (IDA) is anaemic due to the lacking of iron as indicated in low Hb and ferritin levels. IDA affects almost two billion people globally while anaemia without iron deficiency, such as thalassaemia, affects almost 4.5% in Malaysian population. These anaemic conditions have similar clinical symptoms like fatigue, dizziness, in which disturb their cognitive development and productivity in workplace. In areas without proper medical access, many anaemic individuals were misdiagnosed and treated with iron tablets because they were thought to have iron deficiency anaemia due to low Hb content. But, excess iron is toxic to the body. Misdiagnosis can be avoided by iron status assessment. We hereby review the currently available iron status parameters in laboratory and field study with the conclusion of demonstrating the importance of a need for iron reader, in the effort to reduce the prevalence of IDA globally.

Pluripotent stem cells, both embryonic stem cells and induced pluripotent stem cells, are undifferentiated cells that can self-renew and potentially differentiate into all hematopoietic lineages, such as hematopoietic stem cells (HSCs), hematopoietic progenitor cells and mature hematopoietic cells in the presence of a suitable culture system. Establishment of pluripotent stem cells provides a comprehensive model to study early hematopoietic development and has emerged as a powerful research tool to explore regenerative medicine. Nowadays, HSC transplantation and hematopoietic cell transfusion have successfully cured some patients, especially in malignant hematological diseases. Owing to a shortage of donors and a limited number of the cells, hematopoietic cell induction from pluripotent stem cells has been regarded as an alternative source of HSCs and mature hematopoietic cells for intended therapeutic purposes. Pluripotent stem cells are therefore extensively utilized to facilitate better understanding in hematopoietic development by recapitulating embryonic development in vivo, in which efficient strategies can be easily designed and deployed for the generation of hematopoietic lineages in vitro. We hereby review the current progress of hematopoietic cell induction from embryonic stem/induced pluripotent stem cells.

Introduction: Dried blood spots (DBS) are currently the recommended sample collection method for newborn screening programmes in America. Early diagnosis of beta-thalassaemia screening is essential as it provides an added advantage especially in sickle cell disease. Beta-thalassaemia frequency is high in many poor countries, and the cost of using commercial DNA extraction kits can be prohibitive. Our study assessed three methods that use minimal reagents and materials to extract DNA from DBS for beta-thalassaemia identification. Methods: The methods assessed in this study were Tris-EDTA (TE) buffer-based method by Bereczky et al. (American Journal of Tropical Medicine and Hygiene 72, 2005, 249), NaCL/NaOH/Sodium dodecyl sulphate (SDS) method by Huang et al. (Human Genetics 84, 1990, 129) and NaOH method by Zhou et al. (Analytical Biochemistry 354, 2006, 159). Extracted DNA was amplified for three common beta-thalassaemia mutations in Malaysia. Results: Amplicons derived from TE buffer-based method were very faint and almost nonexistent while the NaCl/NaOH/SDS method did not produce any visible amplicons. The extraction using NaOH method produced visible bands that were comparable to the standard method using extraction kit. Conclusion: The NaOH method is a simple method that uses minimal equipment and reagents that make it labour- and cost-effective. This method could be adopted by poorer countries to extract DNA for beta-thalassaemia mutation characterization.

Cytotoxic precipitation of free α-globin monomers and its production of reactive oxygen species cause red cell membrane damage that leads to anemia and eventually ineffective erythropoiesis in β-thalassemia. Alpha hemoglobin stabilizing protein (AHSP) was found to bind only to free α-globin monomers creating a stable and inert complex which remains soluble in the cytoplasm thus preventing harmful precipitations. Alpha hemoglobin stabilizing protein was shown to bind nascent α-globin monomers with transient strength before transferring α-globin to β-globin to form hemoglobin tetramer. A classical twin study would be beneficial to investigate the role of genetics and environment in the variation of alpha hemoglobin stabilizing protein expression as this knowledge will enable us to determine further investigations with regards to therapeutic interventions if alpha hemoglobin stabilizing protein is to be a therapeutic agent for β-thalassemia. This study investigates the heritability influence of alpha hemoglobin stabilizing protein expression and factors that may contribute to this. Results indicated that a major proportion of alpha hemoglobin stabilizing protein expression was influenced by genetic heritability (46%) withcis-acting factors accounting for 19% andtrans-acting factors at 27%.

International audience; It has been suggested that altered levels or function of alpha-haemoglobin stabilising protein (AHSP), an erythroid-specific protein that binds specifically to free alpha-(haemo)globin, might account for some of the clinical variability in beta-thalassaemia. To assess the variation of AHSP expression, mRNA levels in circulating reticulocytes of 103 healthy individuals were measured by quantitative reverse transcription-polymerase chain reaction. AHSP expression varied up to threefold, and did not correlate with age or sex. A systematic survey of the AHSP locus identified eight sequence variants, of which six were common. Four common variants, including the longer homopolymer (T18) in the putative promoter, are strongly associated with AHSP expression. Reporter assays in K562 cells showed that the activity of the shorter (T15) reporter was relatively lower than that of the T18 reporter. In a study of nine anaemic patients who were heterozygous for beta-thalassaemia and also heterozygous for the triplicated alpha-globin gene (alpha alpha alpha/alpha alpha), frequency of the shorter homopolymer was higher than expected. AHSP expression is variable, with cis control accounting for some of its variance. In some families, the subtle altered levels in AHSP related to the AHSP genotype appears to be a relevant contributory factor in the haematological phenotype.

Background The Ts1Cje mouse model of Down syndrome (DS) has partial triplication of mouse chromosome 16 (MMU16), which is partially homologous to human chromosome 21. These mice develop various neuropathological features identified in DS individuals. We analysed the effect of partial triplication of the MMU16 segment on global gene expression in the cerebral cortex, cerebellum and hippocampus of Ts1Cje mice at 4 time-points: postnatal day (P)1, P15, P30 and P84. Results Gene expression profiling identified a total of 317 differentially expressed genes (DEGs), selected from various spatiotemporal comparisons, between Ts1Cje and disomic mice. A total of 201 DEGs were identified from the cerebellum, 129 from the hippocampus and 40 from the cerebral cortex. Of these, only 18 DEGs were identified as common to all three brain regions and 15 were located in the triplicated segment. We validated 8 selected DEGs from the cerebral cortex (Brwd1, Donson, Erdr1, Ifnar1, Itgb8, Itsn1, Mrps6 and Tmem50b), 18 DEGs from the cerebellum (Atp5o, Brwd1, Donson, Dopey2, Erdr1, Hmgn1, Ifnar1, Ifnar2, Ifngr2, Itgb8, Itsn1, Mrps6, Paxbp1, Son, Stat1, Tbata, Tmem50b and Wrb) and 11 DEGs from the hippocampus (Atp5o, Brwd1, Cbr1, Donson, Erdr1, Itgb8, Itsn1, Morc3, Son, Tmem50b and Wrb). Functional clustering analysis of the 317 DEGs identified interferon-related signal transduction as the most significantly dysregulated pathway in Ts1Cje postnatal brain development. RT-qPCR and western blotting analysis showed both Ifnar1 and Stat1 were over-expressed in P84 Ts1Cje cerebral cortex and cerebellum as compared to wild type littermates. Conclusions These findings suggest over-expression of interferon receptor may lead to over-stimulation of Jak-Stat signaling pathway which may contribute to the neuropathology in Ts1Cje or DS brain. The role of interferon mediated activation or inhibition of signal transduction including Jak-Stat signaling pathway has been well characterized in various biological processes and disease models including DS but information pertaining to the role of this pathway in the development and function of the Ts1Cje or DS brain remains scarce and warrants further investigation. Electronic supplementary material The online version of this article (doi:10.1186/1471-2164-15-624) contains supplementary material, which is available to authorized users.

Alpha hemoglobin stabilizing protein (AHSP) was identified in a screen for genes that are activated by the erythroid transcription factor, GATA-1. Studies have shown that: AHSP binds specifically to the α chain of hemoglobin (Hb) but not to β Hb or Hb A; AHSP knock-out mice demonstrated pathological features similar to β thalassemia; and loss of AHSP exacerbates severity of disease in β thalassemia mice. The evidence suggests that AHSP acts as a chaperone for free α Hb and that altered AHSP expression levels could modify the severity of β thalassemia in humans. To assess variation of AHSP expression, mRNA levels were measured in peripheral blood reticulocytes of 103 healthy individuals by quantitative real-time RT-PCR. The sample was approximately 90% (91/103) female with an average age of 52 years (SD=0.14, min=18, max=76). AHSP expression relative to GAPDH, varied up to 3-fold, and did not correlate with age or sex. A systematic survey of the genomic region encompassing the AHSP locus revealed 8 sequence variants of which six were common - five single nucleotide polymorphisms (SNPs), and one homopolymer (Tn) at position 160 bp upstream of exon 1. Four variants (c.-69–237A, c.-69–160 T18, c.-4–27G, and c. 337T) showed strong association with AHSP expression and had nearly equal frequencies. The four variants are in near complete linkage disequilibrium with the minor alleles in coupling. The haplotype consisting of the four minor alleles termed clade B, was associated with relatively lower expression of AHSP. Relative expression of AHSP and AHSP/α globin ratio were both significantly higher (p In conclusion, AHSP gene expression is variable, with cis control accounting for some of its variance. The subtle altered expression might precipitate a phenotype of thalassemia intermedia in β thalassemia heterozygotes with α globin overload.