Severe Thalassemia Research Articles

Loop-mediated isothermal amplification (LAMP) colorimetric phenol red assay for rapid identification of α0-thalassemia: Application to population screening and prenatal diagnosis

BackgroundIdentification of α0-thalassemia (SEA and THAI deletions) is essential in preventing and controlling of severe thalassemia diseases. We have developed the LAMP colorimetric assays for the detection of these two thalassemia defects and validated them in population screening and prenatal diagnosis.MethodsThree LAMP colorimetric assays specific for α0-thalassemia (SEA deletion), α0-thalassemia (THAI deletion) and normal DNA sequence were developed. These assays were validated on 341 subjects who had initial thalassemia screening positive and various thalassemia genotypes. Prenatal diagnosis of α0-thalassemia (SEA deletion) was done on 33 fetuses at risk of having Hb Bart’s hydrops fetalis syndrome.ResultsThe LAMP colorimetric assays for α0-thalassemia (SEA and THAI deletions) could be clearly interpreted by naked eyes. The assay for α0-thalassemia (SEA deletion) showed a 100% (62/62 x 100) sensitivity and 98.2% (274/279 x 100) specificity whereas, that of the α0-thalassemia (THAI deletion) showed 100% (1/1 x 100) sensitivity and 99.7% (339/340 x 100) specificity. We obtained a 100% concordant prenatal diagnosis results using LAMP assays of α0-thalassemia (SEA deletion) in 33 fetuses as compared to the conventional PCR analysis.ConclusionsThe LAMP colorimetric assays developed are simple, rapid, and do not require sophisticated equipment. Inclusion of the LAMP tests in the existing screening protocol significantly reduce the screening cost and the molecular analysis workload, which should prove useful in the prevention and control program of hemoglobinopathies in the region.

Depression symptoms and associated factors among thalassemia patients in the Palestinian Territories: a cross-sectional study

BackgroundThalassemia is a condition that causes the human body to destroy red blood cells faster than they can be made. It causes physical symptomology as well as psychological distress. The current study aimed to identify the prevalence of depression symptoms among individuals with moderate to severe thalassemia. A quantitative descriptive cross-sectional design was applied utilizing the Beck Depression Inventory to assess the level of depression in the sample.ResultsSome significant relationships were demonstrated in the sample: males reporting severe depression symptoms than females by 6.0 times (95% CI 0.07–0.62, p 0.014), and reporting moderate depression symptoms (95% CI 0.00–0.47, p 0.05). Additionally, income was found to be a predictor of level of depression symptoms with low income reported higher incidence of severe depression symptoms than those whose monthly income was > 400$ by 18.4 times (95% CI 0.38–1.03, p ≤ 0.001), but not reporting a significant association between moderate depressive symptoms and monthly income (95% CI − 012–1.47, P 0.225). A significant association was found between the educational attainment and level of depression symptoms with lower levels of education predicting higher levels of severe depression symptoms (95% CI 0.069–0.89, p 0.022), but no significant association was reported between moderate depression symptoms and educational attainment (95% CI − 0.49–0.01, p 0.81).Related to disease characteristics a relationship was confirmed between severe depressive symptoms and medication level such as the individual needing tablets or pumps (95% CI 0.189–1.05, p 0.005 and 95% CI 0.52–1.44, p 0.001) respectively. Other disease related variables showed no significant correlation with depressive symptom levels.Additional significant relationships were found in environment whereas increased moderate depressive symptoms were experienced by individuals residing in rural areas as opposed to those living in IDP camps or cities by 4 times (95% CI − 0.30–0.01, p 0.04), but no significant association was found between severe depression and the place of residence. The other independent variables had no significant correlation with severe or moderate depressive symptoms.ConclusionIn light of these findings addressing symptoms of depression directly and supporting patients with thalassemia with basic life needs unrelated to their disease maybe mitigating depressive symptoms which may negatively affect recovery.

Treatment strategies for haemoglobin E thalassaemia

Thalassaemia is the most common hereditary haemolytic anaemia. Haemoglobin E β-thalassaemia is a type of thalassaemia disease that is prevalent in southeast Asia and parts of the Indian subcontinent, and it accounts for almost half of all patients with severe thalassaemia worldwide.1 Haemoglobin E is caused by a single nucleotide substitution, from GAG to AAG in codon 26 of the HBB gene. The mutation also creates an alternative donor splice site that results in abnormally spliced mRNA.2 Patients with haemoglobin E thalassaemia present with chronic haemolytic anaemia of varying disease severity.

Extended family thalassemia screening as a feasible alternative method to be implemented in identifying carriers in West Java, Indonesia

The thalassemia screening program in Indonesia mostly conducted sporadically. Ideal prospective screening is still limited. This study aimed to compare thalassemia screening methods using the extended family approach with and without a history of severe thalassemia and the feasibility of implementing extended family screening method. A case control study was conducted in Dr. Hasan Sadikin General Hospital Bandung with 3 generations of extended families. Data were collected from 150 subjects of 8 extended families with severe thalassemia as an index case entry and 151 subjects of 12 families with no history of thalassemia. All subjects were examined for Hb, MCV, MCH, and peripheral blood smear (PBS) as initial laboratory examinations. Subjects with MCV < 80 fL, MCH < 27 pg, and suggestive findings on PBS continued hemoglobin analysis. Carrier status was determined by definition. All subjects consented to undergo screening and voluntarily participated. The proportion of thalassemia carriers and the participation rate between the 2 groups were compared. Sixty-four of 150 (42.7%) and 16 of 151 (10.6%) carriers were identified in both the case and control group (p < 0.001). The participation rate was 42–88 vs. 23–100% (p = 0.244). The mean age was 31.9 ± 21.2 vs. 31.1 ± 20.8 years (p = 0.782). The median family size was 28.5 vs. 20 subjects per family (p = 0.245). The types of identified thalassemia carrier in both groups consisted of β-thalassemia, β-thalassemia/HbE, suspected α-thalassemia, and β-thalassemia Hb variant. All carriers continued the counseling process. The extended family method seems feasible to be implemented for thalassemia screening in West Java, Indonesia.

Leg Ulcers: A Report in Patients with Hemoglobin E Beta Thalassemia and Review of the Literature in Severe Beta Thalassemia

Background: Leg ulcers are a frequent complication in patients with the inherited hemoglobin disorders. In thalassemia, the literature is limited, and factors associated with the development of leg ulcers in hemoglobin E (HbE) beta thalassemia, the most common form of severe beta-thalassemia worldwide, have not previously been reported. Methods: We reviewed all available medical records of patients with HbE beta thalassemia to document the onset of leg ulcers at the 2 largest treatment centers in Sri Lanka. We reviewed the literature to identify studies reporting outcomes of interventions for ulcers in severe thalassemia. Results: Of a total of 255 actively registered patients with HbE thalassemia in the 2 centers, 196 patient charts were evaluable. A leg ulcer with a documented date of onset was recorded in 45 (22%) of 196 evaluable patients, aged (mean ± SEM) 22.2 ± 1.4 years. Most had been irregularly transfused; steady-state hemoglobin was 6.4 ± 0.2 g/dL. Treatment achieving healing in 17 patients included transfusions, antibiotics, oral zinc, wound toileting, and skin grafting. Conclusion: Leg ulcers may be more common in HbE beta thalassemia than in other forms of thalassemia. A systematic approach to treatment will be needed to document the prevalence and factors placing such patients at risk for leg ulcers. Controlled trials to evaluate the optimal treatment of this common complication are indicated.

Correction of RNA splicing defect in β654-thalassemia mice using CRISPR/Cas9 gene-editing technology.

β654-thalassemia is a prominent Chinese subtype of β-thalassemia, representing 17% of all cases of β-thalassemia in China. The molecular mechanism underlying this subtype involves the IVS-2-654 C→T mutation leading to aberrant β-globin RNA splicing. This results in an additional 73-nucleotide exon between exons 2 and 3 and leads to a severe thalassemia syndrome. Herein, we explored a CRISPR/Cas9 genome editing approach to eliminate the additional 73-nucleotide by targeting both the IVS-2-654 C→T and a cryptic acceptor splice site at IVS-2-579 in order to correct aberrant β-globin RNA splicing and ameliorate the clinical β-thalassemia syndrome in β654 mice. Gene-edited mice were generated by microinjection of sgRNA and Cas9 mRNA into one-cell embryos of β654 or control mice: 83.3% of live-born mice were gene-edited, 70% of which produced correctly spliced RNA. No off-target events were observed. The clinical symptoms, including hematologic parameters and tissue pathology of all of the edited β654 founders and their offspring were significantly improved compared to those of the non-edited β654 mice, consistent with the restoration of wild-type β-globin RNA expression. Notably, the survival rate of gene-edited heterozygous β654 mice increased significantly, and live-born homozygous β654 mice were observed. Our study demonstrated a new and effective gene-editing approach that may provide groundwork for the exploration of β654-thalassemia therapy in the future.

Identification of optimal thalassemia screening strategies for migrant populations in Thailand using a qualitative approach

BackgroundThalassemia is a common inherited hemoglobin disorder in Southeast Asia. Severe thalassemia can lead to significant morbidity for patients and economic strain for under-resourced health systems. Thailand’s thalassemia prevention and control program has successfully utilized prenatal screening and diagnosis to reduce the incidence of severe thalassemia in Thai populations, but migrant populations are excluded despite having high thalassemia prevalence. We sought to identify key barriers to and facilitators of thalassemia screening and to develop tailored recommendations for providing migrants with access to thalassemia prevention and control.MethodsWe conducted 28 in-depth interviews and 4 focus group discussions (FGDs) in Chonburi, Thailand with Myanmar and Cambodian migrants, Thai healthcare providers, Thai parents of children affected by thalassemia, and migrant agents.ResultsParticipant narratives revealed that migrants’ lack of knowledge about the prevalence, manifestations, severity, and inherited nature of thalassemia led to misconceptions, fear, or indifference toward thalassemia and screening. Negative perceptions of pregnancy termination were based in religious beliefs but compounded by other sociocultural factors, presenting a key obstacle to migrant uptake of prenatal screening. Additionally, structural barriers included legal status, competing work demands, lack of health insurance, and language barriers. Participants recommended delivering public thalassemia education in migrants’ native languages, implementing carrier screening, and offering thalassemia screening in convenient settings.ConclusionsAn effective thalassemia prevention and control program should offer migrants targeted thalassemia education and outreach, universal coverage for thalassemia screening and prenatal care, and options for carrier screening, providing a comprehensive strategy for reducing the incidence of severe thalassemia in Thailand and establishing an inclusive model for regional thalassemia prevention and control.

Direct PCR assays without DNA extraction for rapid detection of hemoglobin Constant Spring and Pakse' genes: application for carrier screening and prenatal diagnosis

Hemoglobin Constant Spring (Hb CS) and Hb Pakse' (PS) are the common non-deletional α+-thalassemia found in Thailand. These two variants can cause severe thalassemia syndromes, especially in fetus and neonate. Molecular diagnosis is the only confirmatory method because Hb CS and Hb PS are usually missed by routine screening and Hb analysis. Therefore, we aimed to develop rapid direct PCR for the diagnosis of Hb CS and PS genes. Multiplex direct PCR assays for identifying the Hb CS and PS genes in whole blood (WB) and amniotic fluid (AF) specimens were developed. The assays were firstly validated on 290 unrelated whole blood specimens. Hb CS and PS carriers were identified in 67 (23.1%) and 6 (2.1%) cases, respectively. A 100% concordant result as compared to routine PCR assay was observed. The direct PCR assays have been applied successfully for prenatal diagnosis in two families. The result showed that the fetuses were affected by homozygous Hb CS and compound heterozygous Hb CS/Hb PS. Accurate prenatal diagnosis of these families was observed using the newly developed assays. These assays should be applicable in routine thalassemia diagnostics as well as in the large-scale screening of Hb CS and PS in the region.

Multiplex Quantitative Real-Time Polymerase Chain Reaction and High-Resolution Melting Analysis for Identification of a Couple At-Risk of Having a Newborn with Severe Thalassemia

Many polymerase chain reaction (PCR)-based techniques have been used for routine diagnosis of α- and β-thalassemias. However, most require a multi step of post-PCR processes that are time-consuming and labor-intensive procedures. This study reported the successful use of multiplex quantitative real-time PCR (qPCR), with high-resolution melting (HRM) analysis for diagnosis of two common deletional α0-thalassemia (α0-thal) and 15 common β-thalassemia (β-thal) mutations, in order to identify a couple at-risk of having a newborn with severe thalassemia in the northern region of Thailand. With this approach, 22 (7.2%) of 306 couples were diagnosed as being at-risk for having a child with severe thalassemia, including three homozygous α0-thal, five homozygous β-thal and 14 Hb E (HBB: c.79G>A)/β0-thal disease. Our findings indicated that multiplex qPCR with HRM is applicable for routine molecular diagnosis in order to identify a couple at-risk of having a newborn with severe thalassemia, especially in an endemic region.

Delayed Anticoagulation Proteins Recovery in Severe Thalassemia Diseases Compared to Malignancies in Children after Hematopoietic Stem Cell Transplantation

Alterations of hemostasis have been observed following hematopoietic stem cell transplantation (HSCT). In thalassemia diseases, the evidences of coagulation stimulation have been observed in patients with thalassemia major with and without splenectomy. The comparison between thalassemia disease before and after HSCT, and malignancy has never been reported. The hemostasis parameters in 8 patients with thalassemia disease and 10 patients with malignancy before, day 0, days 14, days 30, days 60, days 90, and days 180 of HSCT were studied. The median (range) ages in thalassemia, malignancy and normal control groups were 8.5 (2 to 17), 11.0 (2.0 to 19.0) and 10.0 (0 to 16.0) years, respectively (p=0.42). D-dimer level was significantly higher during days 14 to 60 of HSCT in both groups when compared to the normal control group. Protein C and antithrombin activities were significantly lower during HSCT in thalassemia when compared to the malignancy and normal control groups, while, no changes of anticoagulation proteins in malignancy group were observed. Keywords: Stem cell transplantation; Hemostasis; Thalassemia diseases; Malignancy

Impact of Splenomegaly on Outcomes of Fully Matched Sibling Bone Marrow Transplant Among Children with Low Risk Thalassemia

Objective:Severe thalassemia syndromes (ST) are the most common non-infectious life-threatening disease in South Asia. ST is highly curable by BMT but rejection may occur in 5 to 30% of cases. In a limited resource setting appropriate case selection for BMT and aggressive down staging pre-transplant are crucial in order to achieve optimal outcomes. Though hepatomegaly > 2 cm has clearly been proven to be associated with poor transplant outcomes whereas the role of splenomegaly as an independent risk factor for rejection in low risk thalassemia has not been clarified.Methods:We analyzed a total of 87 consecutive first bone marrow transplants carried out between August 2013 and Dec 2016 after conditioning with busulfan (14 mg/kg oral, not adjusted to serum levels), cyclophosphamide (200 mg/kg) and anti-thymocyte globulin (Genzyme 4 mg/kg or Fresenius 16 mg/kg on days -12 to -10). 74 patients received cyclosporine and methotrexate, and 13 patients received cyclosporine and mycophenolate as GVHD/rejection prophylaxis. G-CSF-primed bone marrow (5 μg/kg/dose twice daily for 3 to 5 days prior to harvest) was the source of hematopoietic stem cells in all cases. All patients were considered low risk based on liver size < 2 cm from costal margin and age less than 15 years (median 6.9 years, range 1.1 to 14.5). All sibling couples were HLA-compatible.Results:Of the 87 low risk transplants 12 children rejected (13.8%) of which 5 were primary and 7 were secondary graft failures. Out of the total 87 patients 11 patients had significant splenomegaly at transplant (spleen > 3 cm below costal margin and/or z score > 3 spleen size measured by ultrasound adjusted for height). Four of the rejections (1 primary and 3 secondary) occurred in children with significant splenomegaly which is statistically significant (log rank p=0.02) (figure 1). Splenomegaly also seems to increase treatment-related mortality albeit not statistically significant (log rank p=0.17). Out of the 7 children who had treatment related mortality 2 had splenomegaly. One of them died as a consequence of primary graft failure and the other due to a large intracranial bleed. We could not detect any difference in other variables potentially associated with rejection risk such as gender mismatch, serum ferritin, ABO mismatch, mean cell dose (median 6.75; range 2.6 to 29.44 x 108 nucleated cells /kg) and immunosuppressive therapy between splenomegaly and no splenomegaly groups. In the latter group 41% of children received hydroxyurea pre-BMT compared to 81% in the splenomegaly group (P= 0.01) which in fact should have helped to reduce rejection rates in the splenomegaly group. By multivariate analysis significant splenomegaly (p= 0.0049) seems to be more relevant than gender mismatch in terms of rejection risk (p = 0.0379), while cell dose (p=0.9546) was not a significant factor.Conclusion:Splenomegaly may increase rejection risk in low risk thalassemia transplants transplanted with ATG-BuCy. Strategies to reduce spleen size prior to transplant should be considered. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

The Role of Cyclophosphamide in the Conditioning Regimen of Stem Cell Transplantation in Iron Overload Mice

Background: Hematopoietic stem cell transplantation(HSCT) is the only effective and reliable method for the treatment of severe thalassemia. Most of the transplant centers adopted Busulfan(Bu)/cyclophosphamide(Cy) pretreatment program, the pediatric Transplantation Center of Southern Medical University used “NF-08-TM” pretreatment program based on Cy/Bu achieved remarkable results.Whether the significant achievements related to cyclophosphamide mobilizing hematopoietic stem cells resulting in an increase efficiency of hematopoietic stem cell clearance, has not yet been reported.METHODS: Establish three-levels risk grading standards of iron overload with C57 mice by intraperitoneal injection of dextran iron, based on the domestic recognition three-levels risk grading standards of thalassemia major. Eight groups(d1,d2,d3,d4,d5,d6,d7,d14) were injected intraperitoneally with Cy 50mg / kg for two consecutive days to establish the pretreatment model of transplantation. Peripheral blood cells, BMNNCs, frequencies of different HPCs, HSCs, LT-HSCs in BMMNCs were monitored. The distribution in the cell cycle of HSCs, the level of reactive oxygen species and the microenvironment of HSCs were analyzed by flow cytometry. After N-acetylcysteine anti-oxidation, the above indicators were measured.RESULTS: Compared with the control group, the Serum ferritin in the low, medium and high dose iron group was increased by 7.6 times, 12.8 times and 15.2 times. And the Hepatomegaly Index was increased by 46.9%, 96.5% and 160.2%. Pathological sections showed a large number of iron deposits in the liver, spleen and bone marrow cells, and positively correlated with the dose of iron. Similar to the risk criteria of thalassemia classification, three-level risk model of iron overload was successfully established.Compared with normal mice, the peripheral blood of iron overload model mice did not change significantly, while the number of WBCs and YM% 1d-4d in cyclophosphamide group were significantly decreased (P <0.05),and 7d back to normal; the number of PLT was higher than that of model group and the difference was statistically significant (P <0.05), but there was no significant difference in RBC and HBG.The number of BMNNCs and HPCs in iron overload model mice did not change significantly compared with normal mice,but the number of HSC and LT-HSCs decreased significant (P <0.05); The change rules of BMNNCs and WBC in cyclophosphamide group were the same, and the number of HSCs increased from the first day to the highest in the third day (P <0.05).Compared with normal mice,the cell cycle distribution of HSCs iniron overload model mice did not change significantly, while the proportion of G0 / G1 phase cells in cyclophosphamide group was significantly decreased at the 1st day to the third day(P <0.05). But S and G2 / M phase change the opposite,the difference was statistically significant (P <0.05).After the treatment with NAC, the decrease of G0 / G1 in 1d-3d could be partially reversed(P <0.05). Compared with normal mice,the ROS level of the total bone marrow cells ,HSCs were significantly higher in moderate-risk model mice and cyclophosphamide group, respectively (P <0.05), and the level of ROS in cyclophosphamide groups increased from the first day ,highest in the second day,and then back to normol. After NAC treatment, the level of ROS in cells decreased compare with before respectively (P <0.05).CONCLUSION:The three-level risk model of iron overload was successfully established by treated with different doses of dextran iron intraperitoneally. Iron deposit could lead to long-term hematopoietic stem cell damage, but did not cause significantly changes in peripheral blood.The effect of Cyclophosphamide on mobilization of HSCs in thalassemia transplantation pretreatment regimen may be related to oxidative stress.This study proved initially the advantages of “NF-08-TM” pretreatment in the transplant of thalassemia inour center compared with other transplant centers ,and provided a theoretical basis for further development of individualized pretreatment programs. DisclosuresNo relevant conflicts of interest to declare.

Feasibility of and barriers to thalassemia screening in migrant populations: a cross-sectional study of Myanmar and Cambodian migrants in Thailand

BackgroundThalassemia, an inherited hemoglobin disorder, has become a global public health problem due to population migration. Evidence-based strategies for thalassemia prevention in migrants are lacking. We characterized barriers to thalassemia screening and the burden of thalassemia in migrant workers in Thailand.MethodsMultilingual demographic and KAP surveys were completed by 197 Thai, 119 Myanmar, and 176 Cambodian adults residing in Thailand. Thalassemia awareness, socio-demographic predictors, and knowledge and attitude scores were compared between migrant and Thai subjects. Comprehensive thalassemia testing was performed for migrants.ResultsMigrants had extremely poor thalassemia awareness (4.1%) compared to Thai subjects (79.6%) and had lower thalassemia knowledge scores but similar attitude scores. Surveys identified differing sociodemographic factors predicting awareness in Thai and migrant subjects, as well as key misconceptions likely to hinder thalassemia screening uptake. Nearly all migrants consented to thalassemia testing. We identified abnormal hemoglobin profiles in 52.7% of migrants and a higher projected rate of severe thalassemia births in migrants.ConclusionsThe high burden of thalassemia and tremendous knowledge gap in migrants needs urgent attention. Thalassemia screening was feasible and acceptable in our migrant population. Sociocultural and structural barriers merit further attention when designing thalassemia screening and prevention policies for migrants in Thailand and globally.

Results from 8years of the proficiency testing program for diagnosis of hemoglobinopathies under the prevention and control program of thalassemia in Thailand.

Hemoglobin (Hb) analysis is a key testing for diagnosis of hemoglobinopathies. Accurate analysis, interpretation of results, and genetic risk assessment are important. We report on 8years of the proficiency testing (PT) program for hemoglobinopathies in Thailand. Laboratory participants were required to test two simulated PT items in each cycle using capillary electrophoresis, one was a husband and another was his pregnant wife. Related hematological parameters were provided. The participants also provide interpretation and evaluate the risk of having three severe thalassemia diseases in an expected fetus. Three cycles were operated per year in accordance with the ISO17043 and ISO13528 guidelines. A total of 84 laboratories throughout Thailand were participated. A total of 24 PT cycles were performed during 2012-2019. Most participants had Excellent performance for the PT items with normal, β-thalassemia trait, hemoglobin E trait, hemoglobin E trait with α-thalassemia, and Hb H disease. However, when the PT items with homozygous Hb E and Hb E-β-thalassemia were tested, an increase in a Needs improvement performance was noted. From 24 PT cycles, the performance with Excellent, Good, Fair, and Needs improvement was ranging from 10.5%-95.8%, 0%-11.3%, 0%-77.2%, and 2.3%-37.0%, respectively. Most participants have proven their performance to be reliable and demonstrated their abilities to provide interpretation and genetic risk assessment on most of the PT items. For complex thalassemia however, a need to improve the interpretation and risk assessment skills is required which is essential for effective prevention and control of severe thalassemia diseases in Thailand.

The association between ambient air pollution and birth defects in five major ethnic groups in Liuzhou, China

BackgroundStudies suggest that exposure to ambient air pollution during pregnancy may be associated with increased risks of birth defects (BDs), but conclusions have been inconsistent. This study describes the ethnic distribution of major BDs and examines the relationship between air pollution and BDs among different ethnic groups in Liuzhou city, China.MethodsSurveillance data of infants born in 114 registered hospitals in Liuzhou in 2019 were analyzed to determine the epidemiology of BDs across five major ethnic groups.Concentrations of six air pollutants (PM2.5, PM10, SO2, CO, NO2, O3) were obtained from the Liuzhou Environmental Protection Bureau. Logistic regression was used to examine the associations between ambient air pollution exposure and risk of BDs.ResultsAmong 32,549 infants, 635 infants had BDs, yielding a prevalence of 19.5 per 1000 perinatal infants. Dong ethnic group had the highest prevalence of BDs (2.59%), followed by Yao (2.57%), Miao (2.35%), Zhuang (2.07%), and Han (1.75%). Relative to the Han ethnic group, infants from Zhuang, Miao, Yao and Dong groups had lower risks of congenital heart disease, polydactyly, and hypospadias. The Zhuang ethnic group had higher risks of severe thalassemia, cleft lip and/or palate, and syndactyls. Overall BDs were positively correlated with air pollutants PM10 (aOR =1.14, 95% CI:1.12 ~ 2.43; aOR =1.51, 95% CI:1.13 ~ 2.03 for per 10μg/mg3 increment) and CO (aOR =1.36, 95% CI:1.14 ~ 2.48; aOR =1.75, 95% CI:1.02 ~ 3.61 for every 1 mg /m3 increment) in second and third month of pregnancy. SO2 was also significantly associated with BDs in the second month before the pregnancy (aOR = 1.31; 95% CI: 1.20 ~ 3.22) and third month of pregnancy (aOR =1.75; 95% CI:1.02 ~ 3.61). Congenital heart disease, polydactyl, cleft lip and/or palate were also significantly associated with PM10, SO2 and CO exposures. However, no significant association was found between birth defects and O3, PM2.5 and NO2 exposures (P > 0.05).ConclusionThis study provides a comprehensive description of ethnic differences in BDs in Southwest China and broadens the evidence of the association between air pollution exposure during gestation and BDs.

The Prevalence of HBB Mutations among the Transfusion-Dependent and Non Transfusion-Dependent Hb E/β-Thalassemia Children in a Tertiary Center of West Bengal, India

Hb E (HBB: c.79G>A)/β-thalassemia (Hb E/β-thal) is responsible for nearly half of all the different kinds of severe β-thal. This disorder is characterized by a wide range of clinical variability ranging from mild, asymptomatic non transfusion-dependent thalassemia (NTDT) to severe transfusion-dependent thalassemia (TDT). The aim of the present study was to determine the prevalence of different β-globin gene (HBB) mutations in Hb E/β-thal subjects and their potential role in transfusion dependence. One hundred and ten consecutive children with Hb E/β-thal attending the Pediatric Department of Burdwan Medical College, Burdwan, West Bengal, India were enrolled. Based on hemoglobin (Hb) electrophoresis or high-performance liquid chromatography (HPLC), patients were recruited and later β-globin gene sequencing was done to find out the prevalence of different HBB mutations. Transfusion-dependent thalassemia was seen in 42 children (38.2%), while NTDT was seen in 68 children (61.8%). A total of 10 different β-globin mutant alleles were characterized. The most frequent mutation on the β-globin gene was IVS-I-5 (G>C) (HBB: c0.92+5G>C) in both groups. The β-globin gene mutations alone cannot determine transfusion dependence among the Hb E/β-thal patients.

β-globin gene cluster mutations and large deletions among anaemic patients with elevated HbF level in a tertiary teaching hospital in Kelantan, Malaysia

Mutations in the β-globin gene cluster can lead to β-thalassaemia, δβ-thalassaemia, hereditary persistence of foetal haemoglobin (HPFH) and some of the haemoglobin variants. The clinical and haematological spectrum of thalassaemia range from benign to pathogenic conditions including severe transfusion dependent thalassaemia. Therefore, it is important to accurately diagnose β-globin gene cluster mutations to prevent thalassaemia major or intermedia offspring. The objective of this study is to detect β-globin gene cluster mutations and large deletions among anaemic patients with elevated HbF level in a tertiary teaching hospital in Kelantan, Malaysia. This study involved 144 anaemic patients with HbF level &gt;1.0%. High-Performance Liquid Chromatography (HPLC) was used to determine the HbF and HbA2 levels. Multiplex-ARMS (ARMS)-PCR and gap-PCR were performed for those patients with high HbA2 level (&gt;3.2%) and normal HbA2 level (≤3.2%) to detect β-globin gene cluster mutations and large deletions respectively. The majority of patients were Malays (99.3%) with mean age of 19.99 ± 1.64 years and female 61.1% predominance. Out of 87 samples tested using multiplex ARMS-PCR against eight targeted single mutation; Cd 41/42, IVS 1–5, Cd 26, Cd 17, Cd 71/72, IVS 1–1, Cd 8/9 and -28 mutations, 65 (74.7%) patients were detected which comprises of Cd 26 (56.3%), Cd 41/42 (11.5%), compound Cd 26 and Cd 41/42 (3.4%) and IVS 1–1 (3.4%). Meanwhile, for multiplex gap-PCR which detect four types of large deletions; Thai (δβ)o-thalassaemia, HPFH-6, Siriraj J and Hb Lepore, one out of 57 patients (1.8%) was found positive with Thai (δβ)o-thalassaemia. There was a significant difference between the mean of HbF level, MCV level as well as MCH level of patients with and without β-globin gene mutations and large deletions (P&lt;0.05). This study highlighted the presence of various types of β-globin gene cluster mutations detection in establishing a definitive diagnosis among this selected group of patients for the large-scale screening of the thalassaemia gene.

A Review on Epidemiology and Thalassemia Distribution, in Relevance to United Arab Emirates Population

Thalassemia is a blood disorder passed down through families (inherited) in which the body makes an abnormal form or inadequate amount of hemoglobin. Hemoglobin is the protein in red blood cells that carries oxygen. The disorder results in large numbers of red blood cells being destroyed, which leads to anemia. Depending on the type of mutated globin, there are two types of thalassemia: Alpha- (α-) thalassemia and beta- (β-) thalassemia. It is estimated that around 9 million people suffering from thalassemia become pregnant every year worldwide, of which 1.33 million are at risk of developing severe thalassemia disorder. Thalassemia is a problem in the health sector in many Middle East and North Africa (MENA), region Southeast Asia, Central Asia and the Indian subcontinent. Countries in the MENA region, particularly the Gulf Cooperation Council (GCC) countries and the UAE, have higher prevalence of β-thalassemia and carriers than α-thalassemia. The UAE has the most prevalence of thalassemia carrier among all the MENA countries, due to a huge rate of consanguineous marriage. The UAE government has initiated various measure to reduce the incidences of thalassemia among which one such program included launching of a national campaign in 2008 to promote premarital screening that provides non-instructive genetic counseling to non-at-risk couples. Despite various measures of the thalassemia premarital screening program, the premarital screening program has not been able to effectively reduce the frequency of marriages in high-risk couples in UAE. The study concludes that targeting young people and raising awareness of thalassemia and increasing its burden may reduce inter-carrier marriage and reduce the incidence of such disorders.

Investigation on the Distribution of Common Thalassemias in Various Cities and Counties under the Jurisdiction of Chongzuo City, Guangxi

Objective: To understand the distribution of thalassemia in all districts under the jurisdiction of Chongzuo City. Methods: Collect blood routine indicators from May 2014 to 31 December 2020 in the districts of this city to screen out suspected Mediterranean patients for genetic diagnosis; GGAP-PCR and PCR-reverse dot hybridization were used to analyze the thalassemia gene in the specimens of suspected patients; compare the prevalence of thalassemia in the counties and cities within the jurisdiction of this city, and provide corresponding medical advice to the health authorities. Results: 21,535 venous blood specimens from patients with suspected thalassemia were collected in the city. There were 14,215 positive cases of thalassemia, accounting for 66.01% of the total number of patients, among which 9455 cases (43.91%) were pure α gene positive. 3464 patients (16.09%) were positive for simple β gene. 1296 patients (6.02%) were positive for αβ double gene. The proportions of thalassemia gene testing for α-thalassaemia gene, β-thalassaemia gene, and α-β double gene in various counties and districts were different. According to the multiple rate or the chi-square test of the constituent ratio, the comparison of the distribution of the thalassaemia gene test results in each area, χ2 = 472.6917, P = 0.0000, the difference is statistically significant. Conclusion: Severe thalassemia is a tragedy for a family. It not only needs to spend a lot of money to prolong life, but it also cannot change the situation of losing life and financial emptiness in the end. It is suggested that timely screening, timely diagnosis and medical consultation should be carried out in married and unborn families and early pregnancy, so as to reduce the birth of children with severe thalassemia and avoid the occurrence of tragedies.

Life expectancy and risk factors for early death in patients with severe thalassemia syndromes in South India

In spite of advances in chelation therapy and screening of blood, mortality associated with the most common life-threatening noncommunicable disease of children in India, transfusion-dependent thalassemia (TDT), remains poorly defined. This study aims at estimating death rates and mortality risk factors associated with TDT. The clinical records of 1087 patients from 5 thalassemia centers in India were retrospectively analyzed from 2011 to 2018. Median patient age was 8.5 years, with 107 patients older than 18 years; 656 patients were male and 431 were female. Demographic details and clinical parameters were analyzed at presentation and at last visit. With 41 recorded deaths, actuarial survival at 26.9 years was 50%, and under-5 mortality was 7 times higher than in the general population. Patients with transfusion-transmitted infections (TTIs) had 3.4 times higher risk for death (P = .031). Serum ferritin higher than 4000 ng/dL had 4.6 times higher risk for mortality compared with ferritin lower than 1000 ng/dL (P = .00063). A hemoglobin drop lower than 2 g/dL per week had 7.7 times higher mortality risk compared with a drop of less than 1 g/dL per week (P < .0001). Social determinants (sex, economic status, and distance from center), splenectomy, and even cardiac complications were not associated with higher mortality risk. Main causes of death were infection, iron overload, TTIs, and allo-immunization. Patients who received more than 4 years of adequate care had more than 66% mortality risk reduction (P < .0001). TDT in India continues to result in high mortality. Ineffective transfusion, TTIs, and chelation continue to be the most significant risk factors. Comprehensive care in dedicated day care centers from early age is likely to improve outcomes.