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  1. A case series of α-thalassemia intermedia due to compound heterozygosity for Hb Adana [HBA2: c179G>A (or HBA1); p.Gly60Asp] with other α-thalassemias in Malay families
    Alauddin H, Jaapar NA, Azma RZ, Ithnin A, Razak NF, Loh CK, et al.
    Hemoglobin, 2014;38(4):277-81.
    PMID: 24829075 DOI: 10.3109/03630269.2014.916720
    Hb Adana [HBA2: c179G>A (or HBA1); p.Gly60Asp] is a rare hemoglobin (Hb) variant due to a mutation at codon 59 of the α2- or α1-globin gene resulting in a glycine to aspartic acid substitution. Two siblings with a unique coinheritance of Hb Adana and Hb Constant Spring (Hb CS, α142, Term→Gln, TAA>CAA; HBA2: c.427 T>C) (α(codon 59)α/α(CS)α), were compared phenotypically with another two siblings carrying the Hb Adana mutation and a 3.7 kb deletion (α(codon 59)α/-α(3.7)). Although they all had α-thalassemia intermedia (α-TI), the former were clinically more severe than the latter. The first pair of siblings presented at a much younger age than the second pair and showed lower Hb levels and significant extramedullay hemopoiesis. Another case of a hydropic fetus as a result of Hb H/Hb Adana is also described. Their clinical phenotypes and hematological parameters are all presented for comparison.
  2. Nomenclature Confusion in Deletion Mutations Involving Repetitive Nucleotides: A Lesson from HBB Gene Codon 35 (-C) vs. Codon 36 (-C)
    Rujito L, Sasongko TH, Mulatsih S, Sofro AS
    Hemoglobin, 2015;39(6):452-3.
    PMID: 26291969 DOI: 10.3109/03630269.2015.1069199
  3. Types of thalassemia among patients attending a large university clinic in Kuala Lumpur, Malaysia
    George E, Li HJ, Fei YJ, Reese AL, Baysal E, Cepreganova B, et al.
    Hemoglobin, 1992;16(1-2):51-66.
    PMID: 1634362
    We have identified the beta-thalassemia mutations in 59 patients with thalassemia major and 47 patients with Hb E-beta-thalassemia, and the deletional and nondeletional alpha-thalassemia determinants in 23 out of 24 patients with Hb H disease. All persons were attending the Haematology Clinic at the National University of Malaysia in Kuala Lumpur (Malaysia). Most patients (76) were of Malay descent, while 52 patients were Chinese, and two came from elsewhere. The most frequently occurring beta-thalassemia alleles among the Malay patients were IVS-I-5 (G----C) and G----A at codon 26 (Hb E), while a few others were present at lower frequencies. The Chinese patients carried the mutation characteristic for Chinese [mainly codons 41/42 (-TTCT) and IVS-II-654 (C----T)]; Malay mutations were not observed among Chinese and Chinese mutations were virtually absent in the Malay patients. The large group of patients with Hb E-beta-thalassemia and different beta-thalassemia alleles offered the opportunity of comparing hematological data; information obtained for patients with Hb E-beta-thalassemia living in other countries was included in this comparison. Twenty-three patients with Hb H disease carried the Southeast Asian (SEA) alpha-thalassemia-1 deletion; 13 had the alpha CS alpha (Constant Spring) nondeletional alpha-thalassemia-2 determinant, while the deletional alpha-thalassemia-2 (-3.7 or -4.2 kb) was present in 10 subjects. The --/alpha CS alpha condition appeared to be the most severe with higher Hb H values. Both deletional and nondeletional types of alpha-thalassemia-2 were seen among Malay and Chinese patients.
  4. Molecular basis of beta-thalassemia in the Maldives
    Furuumi H, Firdous N, Inoue T, Ohta H, Winichagoon P, Fucharoen S, et al.
    Hemoglobin, 1998 Mar;22(2):141-51.
    PMID: 9576331
    We have systematically analyzed beta-thalassemia genes using polymerase chain reaction-related techniques, dot-blot hybridization with oligonucleotide probes, allele specific-polymerase chain reaction, and sequencing of amplified DNA fragments from 41 unrelated patients, including 37 beta-thalassemia homozygotes, three with beta-thalassemia/Hb E, and one with beta-thalassemia/Hb S. Four different beta-thalassemia mutations were detected in 78 alleles. These are the IVS-I-5 (G-->C), codon 30 (AGG-->ACG) [also indicated as IVS-I (-1)], IVS-I-1 (G-->A), and codons 41/42 (-TTCT) mutations. The distribution of the beta-thalassemia mutations in the Maldives is 58 alleles (74.3%) with the IVS-I-5 (G-->C) mutation, 12 (15.4%) with the codon 30 (AGG-->ACG) mutation, seven (9%) with the IVS-I-1 (G-->A) mutation, and one with the codons 41/42 (-TTCT) mutation. The first three mutations account for 98.7% of the total number of beta-thalassemia chromosomes studied. These mutations are clustered in the region spanning 6 bp around the junction of exon 1 and the first intervening sequence of the beta-globin gene. These observations have significant implications for setting up a thalassemia prevention and control program in the Maldives. Analysis of haplotypes and frameworks of chromosomes bearing each beta-thalassemia mutation suggested that the origin and spread of these mutations were reflected by the historical record.
    Matched MeSH terms: Hemoglobin E/genetics; Hemoglobin, Sickle/genetics
  5. Hb I-High Wycombe [beta 59(E3)Lys----Glu] in a woman of Malian origin
    Lacombe C, Arous N, Pontet F, Blouquit Y, Bardakdjian J, Riou J, et al.
    Hemoglobin, 1987;11(2):173-6.
    PMID: 3114176
  6. High frequencies of a rearrangement (+ATA; -T) at -530 to the beta-globin gene in different populations indicate the absence of a correlation with a silent beta-thalassemia determinant
    Wong SC, Stoming TA, Efremov GD, Huisman TH
    Hemoglobin, 1989;13(1):1-5.
    PMID: 2703362
    DNA samples from numerous subjects of different racial and ethnic backgrounds, with or without various hemoglobinopathies (classical beta-thalassemia; silent beta-thalassemia, Hb E, sickle cell anemia), were studied for a rearrangement (+ATA; -T) at nucleotide -530 in the 5' flanking region of the beta-globin gene using amplified DNA and 32P-labeled synthetic oligonucleotide probes. The data show that this unusual sequence is a common feature among East-Asians and Blacks (particularly SS patients), and is not associated with mild thalassemic features typical for the silent form of beta-thalassemia, as has been suggested (5).
  7. The thalassemia repository
    Kutler A, Lanclos KD
    Hemoglobin, 1987;11(1):93-109.
    PMID: 3583769
  8. Homozygosity for a new type of G gamma (A gamma delta beta)zero-thalassemia in a Malaysian male
    George E, Faridah K, Trent RJ, Padanilam BJ, Huang HJ, Huisman TH
    Hemoglobin, 1986;10(4):353-63.
    PMID: 2427478
    Hematological and clinical data are presented for a young Malay patient with a homozygous (delta beta)zero-thalassemic condition. His red blood cells contained 100% fetal hemoglobin with alpha and G gamma chains only. Detailed gene mapping defined a large deletion with a 5' end between the Aha III and Apa I sites, some 200-400 bp 5' to the A gamma globin gene and a 3' end beyond sequences 17-18 kb 3' to the beta globin gene. This G gamma (A gamma delta beta)zero-type of thalassemia is different from all the other six types described before. Comparison of the hematological data of this patient with those of homozygotes for either the Sicilian or Spanish types of G gamma A gamma (delta beta)zero-thalassemia showed no differences; all homozygotes have a moderate anemia which is accentuated by the relatively high oxygen affinity of the Hb F containing erythrocytes.
    Matched MeSH terms: Fetal Hemoglobin/genetics
  9. A Unique Interaction of IVS-I-1 (G>A) (HBA2: c.95+1G>A) with Hb Adana (HBA2: c.179G>A) Presenting as Transfusion-Dependent α-Thalassemia
    Alauddin H, Kamarudin K, Loong TY, Azma RZ, Ithnin A, Jalil N, et al.
    Hemoglobin, 2018 Jul;42(4):247-251.
    PMID: 30623696 DOI: 10.1080/03630269.2018.1528985
    Nondeletional α-globin mutations are known to cause more serious clinical effects than deletional ones. A rare IVS-I-1 (G>A) (HBA2: c.95+1G>A) donor splice site mutation interferes with normal splicing of pre mRNA and results in activation of a cryptic splice site as well as a frameshift mutation. Hb Adana [HBA2: c.179G>A (or HBA1)] is a highly unstable variant hemoglobin (Hb) resulting from a mutation at codon 59 on the HBA2 or HBA1 gene, recognized to cause severe α-thalassemia (α-thal) syndromes. We report a unique case of compound heterozygosity for these two mutations in a 9-year-old boy who presented with a Hb level of 5.3 g/dL and hepatomegaly at the age of 15 months. He required regular blood transfusions in view of a Hb level of <7.0 g/dL and failure to thrive. He had thalassemic red cell indices and peripheral blood film. The Hb electrophoresis only showed a raised Hb F level (3.3%) and a pre run peak but the Hb H inclusion test was negative. His father had thalassemic red cell indices but a normal Hb level. His mother had almost normal Hb levels and red cell indices. Hb Adana involving the HBA2 gene was detected by mutiplex amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) in the proband and his father. DNA sequencing of the HBA2 gene confirmed the IVS-I-1 mutation in the proband and his mother. This case highlighted the unique interaction of the IVS-I-1 mutation with Hb Adana in a young Malay boy presenting with transfusion-dependent α-thal.
    Matched MeSH terms: Hemoglobin A2/genetics*
  10. Quadrupole-Time-of-Flight Mass Spectrometric Identification of Hemoglobin Subunits α, β, γ and δ in Unknown Peaks of High Performance Liquid Chromatography of Hemoglobin in β-Thalassemias
    Abdullah UYH, Ibrahim HM, Mahmud NB, Salleh MZ, Kek TL, Noorizhab MNFB, et al.
    Hemoglobin, 2019 May;43(3):182-187.
    PMID: 31298599 DOI: 10.1080/03630269.2019.1632893
    This is the first report of quadrupole time-of-flight (Q-TOF) mass spectrometric identification of the hemoglobin (Hb) subunits, α, β, δ and γ peptides, derived from enzymatic-digestion of proteins in the early unknown peaks of the cation exchange chromatography of Hb. The objectives were to identify the unknown high performance liquid chromatography (HPLC) peaks in healthy subjects and in patients with β-thalassemia (β-thal). The results demonstrate the existence of pools of free globin chains in red blood cells (RBCs). The α-, β-, δ- and γ-globin peptides were identified in the unknown HPLC peaks. The quantification and role of the free globin pool in patients with β-thal requires further investigation. Identification of all types of Hb subunits in the retention time (RT) before 1 min. suggests that altered Hbs is the nature of these fast-eluting peaks. Relevancy of thalassemias to the protein-aggregation disorders will require review of the role of free globin in the pathology of the disease.
    Matched MeSH terms: Hemoglobin Subunits
  11. Genotype-Phenotype Correlation of β-Thalassemia in Malaysian Population: Toward Effective Genetic Counseling
    Abdullah UYH, Ibrahim HM, Mahmud NB, Salleh MZ, Teh LK, Noorizhab MNFB, et al.
    Hemoglobin, 2020 May;44(3):184-189.
    PMID: 32586164 DOI: 10.1080/03630269.2020.1781652
    Effective prevention of β-thalassemia (β-thal) requires strategies to detect at-risk couples. This is the first study attempting to assess the prevalence of silent β-thal carriers in the Malaysian population. Hematological and clinical parameters were evaluated in healthy blood donors and patients with β-thal trait, Hb E (HBB: c.79G>A)/β-thal and β-thal major (β-TM). β-Globin gene sequencing was carried out for 52 healthy blood donors, 48 patients with Hb E/β-thal, 34 patients with β-TM and 38 patients with β-thal trait. The prevalence of silent β-thal carrier phenotypes found in 25.0% of healthy Malaysian blood donors indicates the need for clinician's awareness of this type in evaluating β-thal in Malaysia. Patients with β-TM present at a significantly younger age at initial diagnosis and require more blood transfusions compared to those with Hb E/β-thal. The time at which genomic DNA was extracted after blood collection, particularly from patients with β-TM and Hb E/β-thal, was found to be an important determinant of the quality of the results of the β-globin sequencing. Public education and communication campaigns are recommended as apparently healthy individuals have few or no symptoms and normal or borderline hematological parameters. β-Globin gene mutation characterization and screening for silent β-thal carriers in regions prevalent with β-thal are recommended to develop more effective genetic counseling and management of β-thal.
    Matched MeSH terms: Hemoglobin E/genetics
  12. Hemoglobin Tak in a newborn Malay
    Lie-Injo LE, Randhawa ZI, Ganesan J, Kane J, Peterson D
    Hemoglobin, 1977;1(8):747-57.
    PMID: 604313
    The trait condition for hemoglobin Tak, was found in a 4-day old newborn Malay who suffered from severe neonatal jaundice. The beta chain of the abnormal hemoglobin was elongated by 11 residues at the C-terminus and had the same structure as reported for Hb Tak. The mother was heterozygous for this abnormal hemoglobin, the father was normal. The mother and child, 4 years later, did not show clinical or hematological symptoms except definitely increased resistance of their erythrocytes to hypotonic saline solutions and slight anisopoikilocytosis. The abnormal gene in the two reported Thai families and in our Malay family may have the same origin.
  13. Hb Penang [β78(EF2)Leu→Pro, HBB: c.236T>C]: a Novel β-Globin Variant
    Hsu CH, Langdown J, Lynn R, Fisher C, Rose A, Proven M, et al.
    Hemoglobin, 2018 May;42(3):199-202.
    PMID: 30328734 DOI: 10.1080/03630269.2018.1513849
    We report a novel hemoglobin (Hb) variant with a β chain amino acid substitution at codon 78 (CTG>CCG) (HBB: c.236T>C), detected through prenatal screening via capillary electrophoresis (CE) in an otherwise healthy and asymptomatic 38-year-old female of Southeast Asian ancestry. The variant, named Hb Penang after the proband's Malaysian city of origin, underwent further characterization through high performance liquid chromatography (HPLC), reversed phase HPLC, Sanger sequencing, isopropanol stability testing and isoelectric focusing (IEF).
  14. Prevalence and Risk Factors for Cardiac and Liver Iron Overload in Adults with Thalassemia in Malaysia
    Ngim CF, Lee MY, Othman N, Lim SM, Ng CS, Ramadas A
    Hemoglobin, 2019 Mar;43(2):95-100.
    PMID: 31179787 DOI: 10.1080/03630269.2019.1599906
    We explored the severity and risk factors for cardiac and liver iron overload (IOL) in 69 thalassemia patients who underwent T2* magnetic resonance imaging (T2* MRI) in a Malaysian tertiary hospital from 2011 to 2015. Fifty-three patients (76.8%) had transfusion-dependent thalassemia (TDT) and 16 (23.2%) had non transfusion-dependent thalassemia (NTDT). Median serum ferritin prior to T2* MRI was 3848.0 μg/L (TDT) and 3971.0 μg/L (NTDT). Cardiac IOL was present in 16 (30.2%) TDT patients and two (12.5%) NTDT patients, in whom severe cardiac IOL defined as T2* <10 ms affected six (11.3%) TDT patients. Liver IOL was present in 51 (96.2%) TDT and 16 (100%) NTDT patients, 37 (69.8%) TDT and 13 (81.3%) NTDT patients were in the most severe category (>15 mgFe/gm dry weight). Serum ferritin showed a significantly strong negative correlation with liver T2* in both TDT (rs = -0.507, p = 0.001) and NTDT (r = -0.762, p = 0.002) but no correlation to cardiac T2* in TDT (r = -0.252, p = 0.099) as well as NTDT (r = -0.457, p = 0.100). For the TDT group, regression analysis showed that cardiac IOL was more severe in males (p = 0.022) and liver IOL was more severe in the Malay ethnic group (p = 0.028) and those with higher serum ferritin levels (p = 0.030). The high prevalence of IOL in our study and the poor correlation between serum ferritin and cardiac T2* underline the need to routinely screen thalassemia patients using T2* MRI to enable the early detection of cardiac IOL.
  15. Estimating the Cost of Thalassemia Care across the World: A Thalassemia International Federation Model
    Eleftheriou A, Antoniou E, Darbà J, Ascanio M, Angastiniotis M, Farmakis D
    Hemoglobin, 2022 Nov;46(6):308-311.
    PMID: 36847683 DOI: 10.1080/03630269.2023.2167657
    Estimating the cost of thalassemia care is important for the optimization of care planning, resource allocation and the empowerment of patient advocacy. However, available evidence is heterogeneous, reflecting diverse healthcare systems and cost estimation methods. We sought to build a globally applicable cost model for thalassemia care. We followed a three-step approach, including (i) a targeted literature review to identify previous cost-of-illness studies on thalassemia; (ii) a generic model development based on the main determinants of cost in different countries emerged from a literature review and validated by a team of medical experts; (iii) a piloting of the model using data from two diverse countries. The literature review revealed studies focusing on the total costs of thalassemia care or the cost or cost-effectiveness of specific treatment or prevention modalities in high- and low-prevalence countries across the world. The resulting evidence was used to build a model that calculates total annual therapy cost based on entry of country-level and patient-level data, and data on healthcare modalities, indirect costs and prevention. Testing the model using published data from the UK, Iran, India and Malaysia, revealed an annual cost per patient of £81,796.00 for the UK, Iranian rial (IRR) 13,757.00 for Iran, Indian rupee (INR) 166,750.00 for India and Malyasian ringgit (or dollar) (MYR) 111,372.00 for Malaysia. A globally applicable model that calculates total annual cost of thalassemia care was built based on existing evidence. The model successfully predicted the annual cost of thalassemia care in the UK, Iran, India and Malaysia.
  16. Genotype-Phenotype Study of β-Thalassemia Patients in Sabah
    Suali L, Mohammad Salih FA, Ibrahim MY, Jeffree MSB, Thomas FM, Siew Moy F, et al.
    Hemoglobin, 2022 Nov;46(6):317-324.
    PMID: 36815306 DOI: 10.1080/03630269.2023.2169154
    β-thalassemia is a serious public health problem in Sabah due to its high prevalence. This study aimed to investigate the effects of different types of β-globin gene mutations, coinheritance with α-globin gene mutations, XmnI-Gγ, and rs368698783 polymorphisms on the β-thalassemia phenotypes in Sabahan patients. A total of 111 patients were included in this study. The sociodemographic profile of the patients was collected using a semi-structured questionnaire, while clinical data were obtained from their medical records. Gap-PCR, ARMS-PCR, RFLP-PCR, and multiplex PCR were performed to detect β- and α-globin gene mutations, as well as XmnI-Gγ and rs368698783 polymorphisms. Our data show that the high prevalence of β-thalassemia in Sabah is not due to consanguineous marriages (5.4%). A total of six different β-globin gene mutations were detected, with Filipino β°-deletion being the most dominant (87.4%). There were 77.5% homozygous β-thalassemia patients, 16.2% compound heterozygous β-thalassemia patients, and 6.3% β-thalassemia/Hb E patients. Further evaluation on compound heterozygous β-thalassemia and β-thalassemia/Hb E patients found no concomitant α-globin gene mutations and the rs368698783 polymorphism. Furthermore, the XmnI-Gγ (-/+) genotype did not demonstrate a strong impact on the disease phenotype, as only two of five patients in the compound heterozygous β-thalassemia group and two of three patients in the β-thalassemia/Hb E group had a moderate phenotype. Our findings indicate that the severity of the β-thalassemia phenotypes is closely related to the type of β-globin gene mutations but not to the XmnI-Gγ and rs368698783 polymorphisms.
  17. Adherence to Iron Chelation Therapy Among Children with Beta Thalassemia Major: A Multicenter Cross-Sectional Study
    Keowmani T, Teo SC, Yap KC, Chua WL, Mohd Tahir NF, Chua PW, et al.
    Hemoglobin, 2023 Nov;47(6):237-244.
    PMID: 38111324 DOI: 10.1080/03630269.2023.2295291
    BACKGROUND: Adherence to iron chelation therapy (ICT) remains an issue among thalassemia patients. This study aimed to determine the prevalence of non-adherence to ICT among children with beta thalassemia major in Malaysia and the factors associated with it.

    METHODS: This was a cross-sectional study conducted between November 2019 and November 2021 at seven tertiary hospitals in Malaysia. Participants registered with Malaysian Thalassemia Registry were recruited by convenience sampling. Adherence was measured via pill count and self-reported adherence. Knowledge about thalassemia and ICT was measured using a questionnaire from Modul Thalassemia by Ministry of Health of Malaysia. A decision tree was used to identify predictors of non-adherence.

    RESULTS: A total of 135 patients were recruited. The prevalence of non-adherence to ICT in those who took subcutaneous ± oral medications was 47.5% (95% CI: 31.5%, 63.9%) and the prevalence of non-adherence to ICT in those who took oral medications only was 21.1% (95% CI: 13.4%, 30.6%). The median knowledge score was 67.5% (IQR 15%). A decision tree has identified two factors associated with non-adherence. They were ICT's route of administration and knowledge score. Out of 100 patients who were on oral medications only, 79 were expected to adhere. Out of 100 patients who were on subcutaneous ± oral medications and scored less than 56.25% in knowledge questionnaire, 86 were expected to non-adhere. Based on the logistic regression, the odds of non-adherence in patients who took oral medications only was 71% lower than the odds of non-adherence in patients who took subcutaneous ± oral medications (OR = 0.29; 95% CI = 0.13, 0.65; p = .002).

    CONCLUSION: The prevalence of non-adherence to ICT among children with beta thalassemia major in Malaysia was 20/95 (21.1%) in those who took oral medications only and the prevalence of non-adherence was 19/40 (47.5%) in those who took subcutaneous ± oral medications. The factors associated with non-adherence were ICT's route of administration and knowledge score.

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