Displaying publications 1 - 20 of 24 in total

  1. Teh LK, George E, Lai MI, Tan JA, Wong L, Ismail P
    J Hum Genet, 2014 Mar;59(3):119-23.
    PMID: 24369358 DOI: 10.1038/jhg.2013.131
    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.
    Matched MeSH terms: beta-Globins/genetics
  2. Sivalingam M, Looi ML, Zakaria SZ, Hamidah NH, Alias H, Latiff ZA, et al.
    Int J Lab Hematol, 2012 Aug;34(4):377-82.
    PMID: 22335963 DOI: 10.1111/j.1751-553X.2012.01405.x
    INTRODUCTION: To study the ß-gene mutations spectrum, the genotype/phenotype correlation, the modulatory effect of co-inherited factors such as α-gene mutations and of Xmn1 polymorphism in a large cohort of Malaysian patients.
    METHODS: A total of 264 cases clinically diagnosed as Thalassemia major (TM) (111), Thalassemia intermedia (21), HbE-β Thalassemia (131), and 1 HbE homozygous were studied. The detection of α and ß gene mutations and characterization of Xmn1 polymorphism were performed by multiplex PCR, amplification refractory mutation system (ARMS), DNA sequencing, and restriction fragment length polymorphism (RFLP)-PCR.
    RESULTS: A total of 19 ß Thalassemia mutations were characterized. CD26 and CD41/42 were the most common found in the Malay and Chinese population, respectively. The sensitivity of the clinical diagnosis for β TM, thalassemia intermedia, and HbE/β thalassemia was 94.0%, 15.2%, and 89.2%, respectively. Patients with Xmn1 heterozygosity [+/-] required less frequent transfusion compared with those without the polymorphism. Co-inheritance of α-thalassemia alleviates the severity of HbE-β thalassemia in our cohort.
    CONCLUSION: Molecular analysis should be used for a better diagnosis and management of β thalassemia.
    Matched MeSH terms: beta-Globins/genetics*
  3. Yang Z, Cui Q, Zhou W, Qiu L, Han B
    Mol Genet Genomic Med, 2019 06;7(6):e680.
    PMID: 30968607 DOI: 10.1002/mgg3.680
    BACKGROUND: Thalassemia is a common genetic disorder. High prevalence of thalassemia is found in South China, Southeast Asia, India, the Middle East, and the Mediterranean regions. Thalassemia was thought to exist only in southern China, but an increasing number of cases from northern China have been recently reported.

    METHODS: During 2012 to 2017, suspected thalassemia people were detected for common α- and β-thalassemia mutations by gap-Polymerase Chain Reaction (PCR) and reverse dot blot (RDB) analysis in Peking Union Medical College Hospital. One thousand and fifty-nine people with thalassemia mutations were analyzed retrospectively. We picked mutated individuals who originally came from northern areas, and conducted telephone follow-up survey in order to collect their ancestral information. Besides, we used "thalassemia", "mutation", and "Southeast Asian countries" as keywords to search the relevant studies in PubMed and Embase databases.

    RESULTS: All carriers included in our study were resided in northern China. Among them, 17.3% were native northerners and 82.7% were immigrants from southern China. Although substantial difference was found in α- and β-thalassemia ratio and detailed spectrum of α- and β-globin mutation spectrum between our data and data obtained from a previous meta-analysis literature focused on southern China, the most common gene mutations were the same. Similar β-thalassemia mutation spectrum was found among Thai, Malaysian Chinese, and Guangdong people, however, no other similarities in gene profile were found between Chinese and other ethnic groups in Southeast Asia.

    CONCLUSION: Chinese people in different areas had similar gene mutation, whereas they had significantly different mutation spectrums from other ethnic groups in Southeast Asia.

    Matched MeSH terms: beta-Globins/genetics*
  4. 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.
    Matched MeSH terms: beta-Globins/genetics
  5. Rozitah R, Nizam MZ, Nur Shafawati AR, Nor Atifah MA, Dewi M, Kannan TP, et al.
    Singapore Med J, 2008 Dec;49(12):1046-9.
    PMID: 19122960
    Beta-thalassaemia major is an autosomal recessive disorder that results in severe microcytic, hypochromic, haemolytic anaemia among affected patients. Beta-thalassaemia has emerged as one of the most common public health problems in Malaysia, particularly among Malaysian Chinese and Malays. This study aimed to observe the spectrum of mutations found in Kelantan Malay beta-thalassaemia major patients who attended the Paediatrics Daycare Unit, Hospital Universiti Sains Malaysia, Kelantan, Malaysia, the data of which was being used in establishing the prenatal diagnosis in this Human Genome Centre.
    Matched MeSH terms: beta-Globins/genetics*
  6. Wee, S.Y., Hafiza, A., Azma, R.Z., Azlin, I., Norunaluwar, J., Malisa, M.Y., et al.
    Medicine & Health, 2020;15(1):106-118.
    Hemoglobin S (HbS, α2β26GluVal) merupakan variasi hemoglobin yang terbentuk hasil daripada mutasi GAG GTG pada kodon 6 gen β-globin. Hemoglobinopati haemoglobin S (HbS) jarang ditemui di kalangan penduduk Malaysia tetapi selalunya dijumpai di kalangan pendatang asing dari Afrika. Walau bagaimanapun beberapa kes didapati dalam kaum India dan Melayu. Kajian ini meninjau keputusan makmal pesakit HbS dan penggunaan “multiplex ligation-dependent probe amplification” (MLPA) dan “flow-through hybridization” (FTH) dalam mengesan mutasi HbS. HbS dikenalpasti melalui kromatografi cecair prestasi tinggi (HPLC) dan/atau elektroforesis kapilari serta elektroforesis hemoglobin. Analisis molekul dijalankan menggunakan kaedah MLPA, FTH dan penjujukan Sanger. Dua warga Afrika, tiga Melayu dan dua India berusia antara 2-31 tahun telah dikenalpasti. Lima pesakit adalah HbS homozigot, seorang kompaun heterozigot HbS/β-talasemia dan seorang lagi pembawa HbS. Tahap hemoglobin (Hb) kes HbS homozigot adalah antara 7.4-10.2 g/dL dengan aras HbS dan HbF diantara 58.3-94.7% dan 1.5-35.5%. Hb untuk kes kompaun heterozigot HbS/β-talasemia adalah 5.8 g/dL dan normal pada pembawa HbS. Aras HbS, HbF dan HbA2 untuk HbS/β-talasemia dan pembawa HbS adalah 67%, 27.2% dan 4.2%, dan 38.6%, 0.1% and 2.8% setiap satu. Kedua-dua kaedah MLPA dan FTH berjaya mengesan mutasi HbS dalam semua kes, manakala cuma FTH dapat menentukan zygositi mutasi HbS dan β-talasemia dalam satu ujian yang sama.
    Matched MeSH terms: beta-Globins
  7. Tan JA, Chin SS, Ong GB, Mohamed Unni MN, Soosay AE, Gudum HR, et al.
    Public Health Genomics, 2015;18(1):60-4.
    PMID: 25412720 DOI: 10.1159/000368342
    BACKGROUND: Although thalassemia is a genetic hemoglobinopathy in Malaysia, there is limited data on thalassemia mutations in the indigenous groups. This study aims to identify the types of globin gene mutations in transfusion-dependent patients in Northern Sarawak.
    METHODS: Blood was collected from 32 patients from the Malay, Chinese, Kedayan, Bisayah, Kadazandusun, Tagal, and Bugis populations. The α- and β-globin gene mutations were characterized using DNA amplification and genomic sequencing.
    RESULTS: Ten β- and 2 previously reported α-globin defects were identified. The Filipino β-deletion represented the majority of the β-thalassemia alleles in the indigenous patients. Homozygosity for the deletion was observed in all Bisayah, Kadazandusun and Tagal patients. The β-globin gene mutations in the Chinese patients were similar to the Chinese in West Malaysia. Hb Adana (HBA2:c.179G>A) and the -α(3.7)/αα deletion were detected in 5 patients. A novel 24-bp deletion in the α2-globin gene (HBA2:c.95 + 5_95 + 28delGGCTCCCTCCCCTGCTCCGACCCG) was identified by sequencing. Co-inheritance of α-thalassemia with β-thalassemia did not ameliorate the severity of thalassemia major in the patients.
    CONCLUSION: The Filipino β-deletion was the most common gene defect observed. Homozygosity for the Filipino β-deletion appears to be unique to the Malays in Sarawak. Genomic sequencing is an essential tool to detect rare genetic variants in the study of new populations.
    Matched MeSH terms: beta-Globins/genetics*
  8. Teh LK, Lee TY, Tan JA, Lai MI, George E
    Int J Lab Hematol, 2015 Feb;37(1):79-89.
    PMID: 24725998 DOI: 10.1111/ijlh.12240
    In Malaysia, β-thalassaemia is a common inherited blood disorder in haemoglobin synthesis with a carrier rate of 4.5%. Currently, PCR-incorporating techniques such as amplification refractory mutation system (ARMS) or reverse dot blot hybridization (RDBH) are used in β-thalassaemia mutation detection. ARMS allows single-mutation identification using two reactions, one for wild type and another for mutant alleles. RDBH requires probe immobilization and optimization of hybridization and washing temperatures which is time consuming. The aim of our study was to investigate whether β-thalassaemia mutations can be identified in samples with low DNA concentrations.
    Matched MeSH terms: beta-Globins/genetics*
  9. Harano K, Harano T
    Rinsho Byori, 2010 Apr;58(4):325-31.
    PMID: 20496759
    Hb and gene analyses of a Malaysian mother and her two daughters with microcytic anemia living in Japan were performed. Hb analyses of their hemolysates by IEF and DEAE-HPLC revealed high values of Hb A2 and HbF, but abnormal Hbs such as Hb E and Hb Constant Spring, which cause beta- and alpha-thalassemia traits, were not detected. From these data, they were suspected to be beta-thalassemia carriers. The thalassemic mutations commonly found in the Asian area by ARMS and nucleotide sequencing methods were not detected, and the frameworks of the beta-globin gene and the haplotypes of the beta-like globin gene cluster between the mother and daughters were not identical. These results led us to conclude that there was a beta(0)-thalassemia mutation with a large deletion from the beta-globin gene beyond the 3'beta/BamHI polymorphic site 3' downstream to the beta-globin gene. However, the range of the deletion from the beta-like globin gene cluster has not yet been completed in detail. Recently, there have been many foreigners mainly from Asian countries in Japan. We may encounter people with the rare type thalassemic mutation described in the text besides the mutations frequently found in Asian countries.
    Matched MeSH terms: beta-Globins/genetics*
  10. Chen JJ, Tan JA, Chua KH, Tan PC, George E
    BMJ Open, 2015 Jul 22;5(7):e007648.
    PMID: 26201722 DOI: 10.1136/bmjopen-2015-007648
    OBJECTIVES: Single nucleotide polymorphism (SNP) with a mutation can be used to identify the presence of the paternally-inherited wild-type or mutant allele as result of the inheritance of either allele in the fetus and allows the prediction of the fetal genotype. This study aims to identify paternal SNPs located at the flanking regions upstream or downstream from the β-globin gene mutations at CD41/42 (HBB:c.127_130delCTTT), IVS1-5 (HBB:c.92+5G>C) and IVS2-654 (HBB:c.316-197C>T) using free-circulating fetal DNA.

    SETTING: Haematology Lab, Department of Biomedical Science, University of Malaya.

    PARTICIPANTS: Eight couples characterised as β-thalassaemia carriers where both partners posed the same β-globin gene mutations at CD41/42, IVS1-5 and IVS2-654, were recruited in this study.

    OUTCOME MEASURES: Genotyping was performed by allele specific-PCR and the locations of SNPs were identified after sequencing alignment.

    RESULTS: Genotype analysis revealed that at least one paternal SNP was present for each of the couples. Amplification on free-circulating DNA revealed that the paternal mutant allele of SNP was present in three fcDNA. Thus, the fetuses may be β-thalassaemia carriers or β-thalassaemia major. Paternal wild-type alleles of SNP were present in the remaining five fcDNA samples, thus indicating that the fetal genotypes would not be homozygous mutants.

    CONCLUSIONS: This preliminary research demonstrates that paternal allele of SNP can be used as a non-invasive prenatal diagnosis approach for at-risk couples to determine the β-thalassaemia status of the fetus.

    Matched MeSH terms: beta-Globins/genetics*
  11. Nasri NW, Jamal AR, Abdullah NC, Razi ZR, Mokhtar NM
    Arch Med Res, 2009 Jan;40(1):1-9.
    PMID: 19064120 DOI: 10.1016/j.arcmed.2008.10.008
    Preimplantation genetic diagnosis (PGD) of monogenic autosomal hereditary disorders following assisted conception usually involves the removal of one or two blastomeres from preimplantation embryos. However, the amount of DNA from a single blastomere is insufficient to amplify the region of interest. Hence, the whole genome amplification (WGA) method is performed prior to amplifying the genes of interest before analysis of DNA material through polymerase chain reaction (PCR).
    Matched MeSH terms: beta-Globins/genetics*
  12. Liew PS, Chen Q, Ng AWR, Chew YC, Ravin NV, Sim EUH, et al.
    Anal Biochem, 2019 10 15;583:113361.
    PMID: 31306622 DOI: 10.1016/j.ab.2019.113361
    Phage N15 protelomerase (TelN) cleaves double-stranded circular DNA containing a telomerase-occupancy-site (tos) and rejoins the resulting linear-ends to form closed-hairpin-telomeres in Escherichia coli (E. coli). Continued TelN expression is essential to support resolution of the linear structure. In mammalian cells, no enzyme with TelN-like activities has been found. In this work, we show that phage TelN, expressed transiently and stably in human and mouse cells, recapitulates its native activities in these exogenous environments. We found TelN to accurately resolve tos-DNA in vitro and in vivo within human and mouse cells into linear DNA-containing terminal telomeres that are resistant to RecBCD degradation, a hallmark of protelomerase processing. In stable cells, TelN activity was detectable for at least 60 days, which suggests the possibility of limited silencing of its expression. Correspondingly, linear plasmid containing a 100 kb human β-globin gene expressed for at least 120 h in non-β-globin-expressing mouse cells with TelN presence. Our results demonstrate TelN is able to cut and heal DNA as hairpin-telomeres within mammalian cells, providing a tool for creating novel structures by DNA resolution in these hosts. The TelN protelomerase may be useful for exploring novel technologies for genome interrogation and chromosome engineering.
    Matched MeSH terms: beta-Globins/genetics*
  13. 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).
    Matched MeSH terms: beta-Globins/genetics*
  14. Koh DXR, Raja Sabudin RZA, Mohd Yusoff M, Hussin NH, Ahmad R, Othman A, et al.
    Ann. Hum. Genet., 2017 Sep;81(5):205-212.
    PMID: 28620953 DOI: 10.1111/ahg.12201
    Thalassaemia is a public health problem in Malaysia, with each ethnic group having their own common mutations. However, there is a lack on data on the prevalence and common mutations among the indigenous people. This cross-sectional study was performed to determine the common mutations of α- and β-thalassaemia among the subethnic groups of Senoi, the largest Orang Asli group in Peninsular Malaysia. Blood samples collected from six Senoi subethnic groups were analysed for full blood count and haemoglobin analysis (HbAn). Samples with abnormal findings were then screened for α- and β-globin gene mutations. Out of the 752 samples collected, 255 showed abnormal HbAn results, and 122 cases showing abnormal red cell indices with normal HbAn findings were subjected to molecular screening. DNA analysis revealed a mixture of α- and β-globin gene mutations with 25 concomitant cases. The types of gene abnormalities detected for α-thalassaemia were termination codon (T>C) Hb CS (αCS α), Cd59 (G>A) haemoglobin Adana (Hb Adana) (αCd59 α), initiation codon (ATG>A-G) (αIniCd α), two-gene deletion (-SEA ), and single-gene 3.7-kb deletion (-α3.7 ). For β-thalassaemia, there were Cd26 (G>A) Hb E (βE ), Cd19 (A>G) Haemoglobin Malay (Hb Malay) (βCd19 ), and IVS 1-5 (G>C) (βIVS 1-5 ).
    Matched MeSH terms: beta-Globins/genetics*
  15. Looi ML, Sivalingam M, Husin ND, Radin FZ, Isa RM, Zakaria SZ, et al.
    Clin Chim Acta, 2011 May 12;412(11-12):999-1002.
    PMID: 21315703 DOI: 10.1016/j.cca.2011.02.006
    BACKGROUND: Beta thalassemia represents a great heterogeneity as over 300 mutations have been identified and each population at-risk has its own spectrum of mutations. Molecular characterization with high accuracy, sensitivity and economics is required for population screening and genetic counseling.
    METHODS: We used the MALDI-TOF mass spectrometry (MS) platform to develop novel multiplex assays for comprehensive detection of 27 mutations in beta-thalassemia patients. Six multiplex assays were designed to detect 13 common known ß-mutations, namely CD41/42, CD71/72, IVS1-5, IVS1-1, CD26, IVS2-654, CAP+1, CD19, -28, -29, IVS1-2, InCD (T-G) and CD17; and 14 rare ß-mutations, i.e. InCD (A-C), CD8/9, CD43, -86, CD15, Poly A, Poly T/C, IVS2-1, CD1, CD35/36, CD27/28, CD16, CD37, and 619bpDEL in 165 samples. We compared the efficiencies of genotyping by MS and Amplification Refractory Mutation System (ARMS). Discrepant results were confirmed by sequencing analysis.
    RESULTS: A total of 88.7% (260/293 allele) of MS and ARMS results was in agreement. More than fifty percent of the discrepant result was due to the false interpretation of ARMS results. Failed CD19 assay by MS method might be due to the assay design. The MS method detected 5 rare ß-mutations (CD15, CD35/36, CD8/9, Poly A and Poly T/C) presented in 13 alleles, which were not included in the ARMS screening panel.
    CONCLUSION: We revealed that the MS method is a sensitive, high-throughput, highly automated, flexible, and cost-effective alternative to conventional ß-thalassemia genotyping methods.
    Matched MeSH terms: beta-Globins/genetics*
  16. Lama R, Yusof W, Shrestha TR, Hanafi S, Bhattarai M, Hassan R, et al.
    Hematol Oncol Stem Cell Ther, 2022 Mar 01;15(1):279-284.
    PMID: 33592169 DOI: 10.1016/j.hemonc.2021.01.004
    BACKGROUND: Beta-thalassemia is a genetic disorder that is inherited in an autosomal recessive pattern. This genetic disease leads to a defective beta-globin hemoglobin chain causing partial or complete beta-globin chain synthesis loss. Beta-thalassemia major patients need a continuous blood transfusion and iron chelation to maintain the normal homeostasis of red blood cells (RBCs) and other systems in the body. Patients also require treatment procedures that are costly and tedious, resulting in a serious health burden for developing nations such as Nepal.

    METHODS: A total of 61 individuals clinically diagnosed to have thalassemia were genotyped with multiplex amplification refractory mutation system-polymerase chain reaction (ARMS-PCR). Twenty-one major mutations were investigated using allele-specific primers grouped into six different panels.

    RESULTS: The most common mutations found (23%) were IVS 1-5 (G-C) and Cd 26 (G-A) (HbE), followed by 619 deletion, Cd 8/9 (+G), Cd 16 (-C), Cd 41/42 (-TTCT), IVS 1-1 (G-T), Cd 19 (A-G), and Cd 17 (A-T) at 20%, 12%, 8%, 6%, 4%, 3%, and 1%, respectively.

    CONCLUSION: The results of this study revealed that Nepal's mutational profile is comparable to that of its neighboring countries, such as India and Myanmar. This study also showed that thalassemia could be detected across 17 Nepal's ethnic groups, especially those whose ancestors originated from India and Central Asia.

    Matched MeSH terms: beta-Globins/genetics
  17. Rahimah A, Syahira Lazira O, Siti Hida HM, Faidatul Syazlin AH, Nur Aisyah A, Nik Hafidzah NM, et al.
    Med J Malaysia, 2014 Feb;69(1):42-3.
    PMID: 24814631 MyJurnal
    Haemoglobin S D-Punjab is a rare compound heterozygous haemoglobinopathy characterised by the presence of two β globin gene variants: Β6(GAG→GTG) and Β121(GAA→CAA). These patients' clinical and haematological features mimic haemoglobin S disease. We describe the first case of doubly heterozygous HbSD-Punjab from Malaysia managed with regular blood transfusion at the age of one. This case highlights the propensity for occurrence of rare phenotypes within our multi-ethnic population and emphasises the importance of accurate genotyping to avoid erroneous counselling, and to plan an effective patient management strategy before complication evolves.
    Matched MeSH terms: beta-Globins
  18. George E, Jamal AR, Khalid F, Osman KA
    Malays J Med Sci, 2001 Jul;8(2):40-6.
    PMID: 22893759 MyJurnal
    Beta-thalassaemia is characterized by a decrease (β(+)) or absence (β(0)) in the synthesis of β-globin chains of human haemoglobin. The heterozygous state for β(+) or β(0) result in β-thalassaemia trait in which the hallmark is the presence of an elevated level of Haemoglobin (Hb) A(2) (α(2)δ(2)). In the past, the traditional methods such as cellulose acetate electrophoresis with elution and microcolumn chromatrography have been the techniques used by the majority of the laboratories in Malaysia for the estimation of (Hb) A(2) levels. The recommended method currently is high performance liquid chromatography which has only been introduced in a few laboratories in the country.
    Matched MeSH terms: beta-Globins
  19. Loong TY, Chong DL, Jamal AR, Murad NA, Sabudin RZ, Fun LC
    EXCLI J, 2016;15:630-635.
    PMID: 28096792 DOI: 10.17179/excli2016-613
    Haemoglobin (Hb)-M Hyde Park, also known as Hb-M Akita is a rare type of hereditary Hb M due to autosomal dominant mutation of CAC>TAC on codon 92 of β globin gene resulting in the replacement of histidine by tyrosine on β globin chain. This variant Hb has a tendency to form methaemoglobin (metHb). The iron ion in metHb is oxidized to ferric (Fe3+) which is unable to carry oxygen and the patients manifest as cyanosis clinically. A 9-year-old Malay girl was incidentally found to be cyanotic when she presented to a health clinic. Laboratory investigations revealed raised methaemoglobin levels and Hb analysis findings were consistent with Hb-M Hyde Park. β gene sequencing confirmed a point mutation of CAC>TAC on codon 92 in one of the β genes. The family study done on the individuals with cyanosis showed similar findings. A diagnosis of heterozygous Hb-M Hyde Park was made. Patients with this variant Hb usually presented with cyanosis with mild haemolysis and maybe misdiagnosed as congenital heart disease. No further treatment is needed as patients are relatively asymptomatic. Although the disease is harmless in the heterozygous carriers but the offspring of the carriers may suffer severe haemolytic anaemia when the offspring also inherit other β haemoglobinopathies/thalassemia. This can happen due to high prevalence of β thalassemia carrier (3.5-4 %) found in Malaysia. At the time of writing, this is the first case of hereditary Hb-M Hyde Park diagnosed in a Malay family living in Malaysia.
    Matched MeSH terms: beta-Globins
  20. George E, Teh LK, Tan J, Lai MI, Wong L
    Pathology, 2013 01;45(1):62-5.
    PMID: 23222244 DOI: 10.1097/PAT.0b013e32835af7c1
    AIMS: Classical carriers of β-thalassaemia are identified by a raised HbA2 level. Earlier studies indicated that the Filipino β-deletion has high raised HbA2 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 HbA2 levels in thalassaemia screening. This study aimed to determine HbA2 levels in carriers of Filipino β-mutation using the BioRad Variant II Hb analyser.

    METHODS: The Filipino β-deletion was identified using gap-polymerase chain reaction (PCR) in the parents of transfusion dependent β-thalassaemia patients who were homozygous for the Filipino β-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 HbA2 level for Filipino β-thalassaemia trait was 5.9 ± 0.47 and with coinheritance of α-thalassaemia was 6.3 ± 0.44 (-α heterozygous) and 6.7 ± 0.36 (-α homozygous). The HbA2 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 HbA2 level measured on the BioRad Variant II Hb analyser was lower than the level in the first description of the Filipino β-thalassaemia. β-thalassaemia trait with coinheritance of α-thalassaemia (-α) is associated with significantly higher HbA2 level.

    Matched MeSH terms: beta-Globins/genetics
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