Displaying publications 1 - 20 of 123 in total

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  1. Zarina AL, Hamidah A, Zulkifli SZ, Jamal R
    PMID: 15916058
    Thalassemia is the commonest hemoglobinopathy in Malaysia. Patients with thalassemia major are transfusion dependent, and a large proportion of them will require splenectomy. As this particular group of patients is immunocompromized, overwhelming sepsis is a recognized complication. We report a series of three patients who all developed intra-abdominal abscesses following splenectomy.
    Matched MeSH terms: beta-Thalassemia/complications; beta-Thalassemia/surgery*
  2. Yatim NF, Rahim MA, Menon K, Al-Hassan FM, Ahmad R, Manocha AB, et al.
    Int J Mol Sci, 2014 May 19;15(5):8835-45.
    PMID: 24857915 DOI: 10.3390/ijms15058835
    Both α- and β-thalassaemia syndromes are public health problems in the multi-ethnic population of Malaysia. To molecularly characterise the α- and β-thalassaemia deletions and mutations among Malays from Penang, Gap-PCR and multiplexed amplification refractory mutation systems were used to study 13 α-thalassaemia determinants and 20 β-thalassaemia mutations in 28 and 40 unrelated Malays, respectively. Four α-thalassaemia deletions and mutations were demonstrated. --SEA deletion and αCSα accounted for more than 70% of the α-thalassaemia alleles. Out of the 20 β-thalassaemia alleles studied, nine different β-thalassaemia mutations were identified of which βE accounted for more than 40%. We concluded that the highest prevalence of (α- and β-thalassaemia alleles in the Malays from Penang are --SEA deletion and βE mutation, respectively.
    Matched MeSH terms: beta-Thalassemia/genetics*; beta-Thalassemia/pathology
  3. Wong YY, Alauddin H, Raja Sabudin RZA, Ithnin A, Jalil N, Abdul Latiff Z, et al.
    Malays J Pathol, 2021 Apr;43(1):95-100.
    PMID: 33903312
    The Siriraj I Gγ(Aγδβ)0-thalassaemia is a novel mutation involving a 118kb deletion of the β-globin gene cluster. It was first reported in 2012 in two unrelated families from the southern part of Thailand. The carriers in the heterozygous state are clinically asymptomatic. Nonetheless, its complex interaction with other β-thalassaemia could give rise to different clinical phenotypes, ranging from mild thalassaemia intermedia to thalassaemia major. We report here a case of a six-year-old Malay boy, presented with pallor, growth failure and hepatosplenomegaly. His haemoglobin at presentation was 9.2g/dL with a mean cell haemoglobin of 22.6pg and a mean cell volume of 69.9fl. His peripheral blood smear showed features of thalassaemia intermedia. Haemoglobin (Hb) analysis revealed markedly raised Hb F (83%), normal HbA2 levels and absent HbA. Deoxyribonucleic acid (DNA) analysis showed compound heterozygous IVS1-1 (G→T) β-globin gene mutation and Siriraj I Gγ(Aγδβ)0-deletion (genotype βIVS1-1/ β Siriraj I deletion). Both his father and elder sister are carriers of Siriraj I Gγ(Aγδβ)0-thalassaemia while his mother carries IVS1-1 (G→T) gene mutation. Clinically, the patient is transfusion dependent on six weekly regime. To the best of our knowledge, this is the first reported case in Malaysia involving unique Siriraj I Gγ(Aγδβ)0-thalassaemia and IVS1-1 (G→T) in a compound heterozygous state. In summary, detection of Siriraj I Gγ(Aγδβ)0-thalassaemia is essential as this deletion can lead to severe disease upon interaction with a β-thalassemia point mutation as demonstrated in our case. The establishment of effective carrier screening and genetic counselling is important to prevent its adverse consequences.
    Matched MeSH terms: beta-Thalassemia
  4. Wong YC, George E, Tan KL, Yap SF, Chan LL, Tan JA
    Malays J Pathol, 2006 Jun;28(1):17-21.
    PMID: 17694955
    The molecular basis of variable phenotypes in P-thalassaemia patients with identical genotypes has been associated with co-inheritance of alpha-thalassaemia and persistence of HbF production in adult life. The Xmn I restriction site at -158 position of the Ggamma-gene is associated with increased expression of the Ggamma-globin gene and higher production of HbF This study aims to determine the frequency of the digammaferent genotypes of the Ggamma Xmn I polymorphism in P-thalassaemia patients in two ethnic groups in Malaysia. Molecular characterisation and frequency of the Ggamma Xmn I polymorphism were studied in fifty-eight Chinese and forty-nine beta-thalassaemia Malay patients by Xmn I digestion after DNA amplification of a 650 bp sequence. The in-house developed technique did not require further purification or concentration of amplified DNA before restriction enzyme digestion. The cheaper Seakem LE agarose was used instead of Nusieve agarose and distinct well separated bands were observed. Genotyping showed that the most frequent genotype observed in the Malaysian Chinese was homozygosity for the absence of the Xmn I site (-/-) (89.7%). In the Malays, heterozygosity of the Xmn I site (+/-) was most common (63.3%). Homozygosity for the Xmn I site (+/+) was absent in the Chinese, but was confirmed in 8.2% of the Malays. The ratio of the (+) allele (presence of the Xmn I site) to the (-) allele (absence of the Xmn I site)) was higher in the Malays (0.66) compared to the Chinese (0.05). The (+/-) and (+/+) genotypes are more commonly observed in the Malays than the Chinese in Malaysia.
    Matched MeSH terms: beta-Thalassemia/genetics*
  5. Wong LP, George E, Tan JA
    J Community Genet, 2011 Jun;2(2):71-9.
    PMID: 22109791 DOI: 10.1007/s12687-011-0039-z
    Hemoglobin disorders which include thalassemias are the most common heritable disorders. Effective treatment is available, and these disorders can be avoided as identification of carriers is achievable using simple hematological tests. An in-depth understanding of the awareness, attitudes, perceptions, and screening reservations towards thalassemia is necessary, as Malaysia has a multi-ethnic population with different religious beliefs. A total of 13 focus group discussions (70 participants) with members of the general lay public were conducted between November 2008 and January 2009. Lack of knowledge and understanding about thalassemia leads to general confusions over differences between thalassemia carriers and thalassemia major, inheritance patterns, and the physical and psychologically impact of the disorder in affected individuals and their families. Although most of the participants have not been tested for thalassemia, a large majority expressed willingness to be screened. Views on prenatal diagnosis and termination of fetuses with thalassemia major received mixed opinions from participants with different religions and practices. Perceived stigma and discrimination attached to being a carrier emerged as a vital topic in some group discussions where disparity in the answers exhibited differences in levels of participants' literacy and ethnic origins. The two most common needs identified from the discussion were information and screening facilities. Participants' interest in knowing the severity of the disease and assessing their risk of getting the disorder may imply the health belief model as a possible means of predicting thalassemia public screening services. Findings provide valuable insights for the development of more effective educational, screening, and prenatal diagnostic services in the multi-ethnic Asian society.
    Matched MeSH terms: beta-Thalassemia
  6. Wee YC, Tan KL, Kuldip K, Tai KS, George E, Tan PC, et al.
    Community Genet, 2008;11(3):129-34.
    PMID: 18376108 DOI: 10.1159/000113874
    BACKGROUND/AIMS: Individuals with double heterozygosity for alpha- and beta-thalassaemia and heterozygous beta-thalassaemia show a similar haematological picture. Co-inheritance of alpha- and beta-thalassaemia in both partners may result in pregnancies with either Hb Bart's hydrops foetalis or beta-thalassaemia major, or pregnancies with both disorders.
    METHODS: The co-inheritance of alpha-thalassaemia in 322 beta-thalassaemia carriers in Malaysia was studied.
    RESULTS: The frequency of alpha-thalassaemia in the beta-thalassaemia carriers was 12.7% (41/322), with a carrier frequency of 7.8% for the SEA deletion, 3.7% for the -alpha(3.7) deletion, 0.9% for Hb Constant Spring and 0.3% for the -alpha(4.2) deletion.
    CONCLUSION: Double heterozygosity for alpha- and beta-thalassaemia was confirmed in 5 out of the 41 couples and the risk of the fatal condition Hb Bart's hydrops foetalis was confirmed in two of these couples. Detection of the Southeast Asian (SEA) deletion in the Malaysian Malays in this study confirms that Hb Bart's hydrops foetalis can occur in this ethnic group. Results of this study have provided new information on the frequency and different types of alpha-thalassaemia (--(SEA), -alpha(3.7) and -alpha(4.2) deletions, Hb Constant Spring) in Malaysian beta-thalassaemia carriers.
    Matched MeSH terms: beta-Thalassemia/diagnosis; beta-Thalassemia/ethnology; beta-Thalassemia/genetics*
  7. Wee SY, Muhamed Said SS, Raja Sabudin RZA, Alauddin H, Ithnin A
    Malays J Pathol, 2020 Aug;42(2):195-201.
    PMID: 32860371
    INTRODUCTION: Differentiating between thalassaemia and iron deficiency anaemia (IDA) in hypochromic anaemia is a challenge to pathologists as it influences the choice of subsequent specialized confirmatory tests. In this study, we aimed to evaluate the performance of microcytic to hypochromic ratio (MicroR/ Hypo-He, M/H ratio) as a discriminant index in hypochromic anaemia.

    MATERIALS AND METHODS: A retrospective study was carried out on 318 subjects with hypochromic anaemia, which comprised 162 IDA and 156 thalassaemia trait subjects with α-thalassemia, β-thalassemia and HbE trait. Optimal cut-off value, sensitivity and specificity of M/H ratio for thalassaemia trait discrimination was determined using Receiver Operating Characteristic (ROC) analysis.

    RESULTS: Subjects with thalassaemia trait showed higher MicroR compared to IDA ( p< 0.001) while subjects with IDA demonstrated higher Hypo-He than thalassaemia trait (p < 0.001). M/H ratio was significantly higher in thalassaemia trait compared to IDA, with medians of 3.77 (interquartile range: 2.57 - 6.52) and 1.73 (interquartile range: 1.27 - 2.38), respectively (p < 0.001). M/H ratio ≥ 2.25 was the optimal cut-off value for discriminating thalassaemia trait from IDA in hypochromic anaemia, with the area under ROC curve (AUC) of 0.83, sensitivity of 80.8% and specificity of 71.6%.

    CONCLUSIONS: M/H ratio is a useful discriminant index to distinguish thalassaemia trait from IDA in hypochromic anaemia prior to diagnostic analysis for thalassaemia confirmation. High M/H ratio is suggestive of thalassaemia trait than of IDA. However, more studies are required to establish the role of M/H ratio as a screening tool for thalassaemia discrimination in hypochromic anaemia.

    Matched MeSH terms: beta-Thalassemia/diagnosis; beta-Thalassemia/pathology
  8. Wan Juhari WK, Md Tamrin NA, Mat Daud MH, Isa HW, Mohd Nasir N, Maran S, et al.
    Hugo J, 2014 Dec;8(1):4.
    PMID: 27090252 DOI: 10.1186/s11568-014-0004-0
    BACKGROUND: The sequencing of two members of the Royal Kelantan Malay family genomes will provide insights on the Kelantan Malay whole genome sequences. The two Kelantan Malay genomes were analyzed for the SNP markers associated with thalassemia and Helicobacter pylori infection. Helicobacter pylori infection was reported to be low prevalence in the north-east as compared to the west coast of the Peninsular Malaysia and beta-thalassemia was known to be one of the most common inherited and genetic disorder in Malaysia.

    RESULT: By combining SNP information from literatures, GWAS study and NCBI ClinVar, 18 unique SNPs were selected for further analysis. From these 18 SNPs, 10 SNPs came from previous study of Helicobacter pylori infection among Malay patients, 6 SNPs were from NCBI ClinVar and 2 SNPs from GWAS studies. The analysis reveals that both Royal Kelantan Malay genomes shared all the 10 SNPs identified by Maran (Single Nucleotide Polymorphims (SNPs) genotypic profiling of Malay patients with and without Helicobacter pylori infection in Kelantan, 2011) and one SNP from GWAS study. In addition, the analysis also reveals that both Royal Kelantan Malay genomes shared 3 SNP markers; HBG1 (rs1061234), HBB (rs1609812) and BCL11A (rs766432) where all three markers were associated with beta-thalassemia.

    CONCLUSIONS: Our findings suggest that the Royal Kelantan Malays carry the SNPs which are associated with protection to Helicobacter pylori infection. In addition they also carry SNPs which are associated with beta-thalassemia. These findings are in line with the findings by other researchers who conducted studies on thalassemia and Helicobacter pylori infection in the non-royal Malay population.

    Matched MeSH terms: beta-Thalassemia
  9. Viprakasit V, Lee-Lee C, Chong QT, Lin KH, Khuhapinant A
    Int J Hematol, 2009 Nov;90(4):435-445.
    PMID: 19862602 DOI: 10.1007/s12185-009-0432-0
    Worldwide, thalassemia is the most commonly inherited hemolytic anemia, and it is most prevalent in Asia and the Middle East. Iron overload represents a significant problem in patients with transfusion-dependent beta-thalassemia. Chelation therapy with deferoxamine has traditionally been the standard therapeutic option but its usage is tempered by suboptimal patient compliance due to the discomfort and demands associated with the administration regimen. Therefore, a great deal of attention has been focused on the development of oral chelating agents. Deferiprone, even though available for nearly two decades in Asia with recent encouraging data on cardiac iron removal and long-term efficacy, has serious adverse effects including agranulocytosis and neutropenia which has impeded it from routine clinical practice. A novel oral chelator; deferasirox is effective throughout a 24 h dosing period and both preclinical and clinical data indicate that it successfully removes both hepatic and cardiac iron. In Asia, optimal management of severe thalassemia patients and the availability and access to oral iron chelators still presents a major challenge in many countries. In this regard, the development and implementation of consensus guidelines for management of Asian patients with transfusion-dependent thalassemia will be a major step towards improving and maintaining the continuity of patient care.
    Matched MeSH terms: beta-Thalassemia/economics; beta-Thalassemia/epidemiology; beta-Thalassemia/therapy
  10. Van Ziffle J, Yang W, Chehab FF
    PLoS One, 2011;6(2):e17327.
    PMID: 21390308 DOI: 10.1371/journal.pone.0017327
    Progress in the functional studies of human olfactory receptors has been largely hampered by the lack of a reliable experimental model system. Although transgenic approaches in mice could characterize the function of individual olfactory receptors, the presence of over 300 functional genes in the human genome becomes a daunting task. Thus, the characterization of individuals with a genetic susceptibility to altered olfaction coupled with the absence of particular olfactory receptor genes will allow phenotype/genotype correlations and vindicate the function of specific olfactory receptors with their cognate ligands. We characterized a 118 kb β-globin deletion and found that its 3' end breakpoint extends to the neighboring olfactory receptor region downstream of the β-globin gene cluster. This deletion encompasses six contiguous olfactory receptor genes (OR51V1, OR52Z1, OR51A1P, OR52A1, OR52A5, and OR52A4) all of which are expressed in the brain. Topology analysis of the encoded proteins from these olfactory receptor genes revealed that OR52Z1, OR52A1, OR52A5, and OR52A4 are predicted to be functional receptors as they display integral characteristics of G-proteins coupled receptors. Individuals homozygous for the 118 kb β-globin deletion are afflicted with β-thalassemia due to a homozygous deletion of the β-globin gene and have no alleles for the above mentioned olfactory receptors genes. This is the first example of a homozygous deletion of olfactory receptor genes in human. Although altered olfaction remains to be ascertained in these individuals, such a study can be carried out in β-thalassemia patients from Malaysia, Indonesia and the Philippines where this mutation is common. Furthermore, OR52A1 contains a γ-globin enhancer, which was previously shown to confer continuous expression of the fetal γ-globin genes. Thus, the hypothesis that β-thalassemia individuals, who are homozygous for the 118 kb deletion, may also have an exacerbation of their anemia due to the deletion of two copies of the γ-globin enhancer element is worthy of consideration.
    Matched MeSH terms: beta-Thalassemia/classification; beta-Thalassemia/genetics*; beta-Thalassemia/metabolism
  11. VELLA F
    Med J Malaya, 1959 Dec;14:116-21.
    PMID: 13841623
    Matched MeSH terms: beta-Thalassemia/etiology*
  12. Thong MK, Tan JA, Tan KL, Yap SF
    J Trop Pediatr, 2005 Dec;51(6):328-33.
    PMID: 15967770 DOI: 10.1093/tropej/fmi052
    beta-thalassaemia major, an autosomal recessive hemoglobinopathy, is one of the most common single gene disorders in multi-racial Malaysia. The control of beta-thalassaemia major requires a multi-disciplinary approach that includes population screening, genetic counselling, prenatal diagnosis and the option of termination of affected pregnancies. To achieve this objective, the molecular characterisation of the spectrum of beta-globin gene mutations in each of the affected ethnic groups is required. We studied 88 consecutive unrelated individuals and their respective families with beta-thalassaemia (74 beta-thalassaemia major, 12 HbE-beta-thalassaemia, 2 with HbE homozygotes) and four individuals with beta-thalassaemia trait that contributed a total 180 alleles for study. Using a 2-step molecular diagnostic strategy consisting of amplification refractory mutation system (ARMS) to identify the 8 most common mutations followed by other DNA-based diagnostic techniques, a total of 177 (98.3 per cent) of the 180 beta-thalassaemia alleles were characterised. One out of 91 (1 per cent) of the Chinese alleles, one out of 46 (2.2 per cent) Malay alleles and one out of two Indian alleles remained unknown. A 100 per cent success rate was achieved in studying the Kadazandusun community in this study. A strategy to identify beta-globin gene mutations in Malaysians with beta-thalassaemia is proposed based on this outcome.
    Matched MeSH terms: beta-Thalassemia/diagnosis; beta-Thalassemia/ethnology; beta-Thalassemia/genetics*
  13. Thong MK, Rudzki Z, Hall J, Tan JA, Chan LL, Yap SF
    Hum Mutat, 1999;13(5):413.
    PMID: 10338100 DOI: 10.1002/(SICI)1098-1004(1999)13:5<413::AID-HUMU15>
    Beta-thalassemia major is one of the commonest genetic disorders in South-East Asia. The spectrum of beta-thalassemia mutations in the various ethnic sub-populations on the island of Borneo is unknown. We studied 20 Dusun children from the East Malaysian state of Sabah (North Borneo) with a severe beta-thalassemia major phenotype, using a combination of Southern analysis, polymerase chain reaction analysis and direct sequencing. We found the children to be homozygous for a large deletion, which has a 5' breakpoint at position -4279 from the cap site of the beta-globin gene (HBB) with the 3' breakpoint located in a L1 family of repetitive sequences at an unknown distance from the beta-globin gene. This was similar to a recent finding of a large deletion causing beta-thalassemia first described in unrelated beta-thalassemia heterozygotes of Filipino descent. This report describes the first 20 families with homozygosity of the deletion causing a severe phenotype. It provides the first information on the molecular epidemiology of beta-thalassemia in Sabah. This finding has implications for the population genetics and preventative strategies for beta-thalassemia major for nearly 300 million individuals in South-East Asia.
    Matched MeSH terms: beta-Thalassemia/genetics*
  14. Thong MK, Law HY, Ng IS
    Ann Acad Med Singap, 1996 Jan;25(1):79-83.
    PMID: 8779552
    The beta-thalassaemia mutations in 20 Malaysian children with beta-thalassaemia major were characterised by using a multi-modal approach, consisting of a slot-blot hybridisation with selected allele-specific oligonucleotides (ASO), followed by reverse dot-blot assay (RDB), amplification refractory mutation system (ARMS) and genomic sequencing. This strategy yielded a 94.4% mutation detection rate. The 6 most common mutations were codons 41/42 (-TTCT), IVS II nt 654(C --> T), IVS I nt 5(G --> C), IVS I nt 1(G -->T), codon 35 (-C) and codon 19 (A --> G), which accounted for 83.3% of all mutations detected. A strategy of initial screening with the above 6 selected ASOs for slot-blot hybridisation followed by RDB assay for the less common Asian mutations would give a mutation identification of 91.7%. Another feasible approach would be to analyse alleles from a particular racial group, by a judicious selection of 4 ASOs common to that particular subpopulation and then supplement this with RDB assay. This could yield a 100% coverage for the Chinese subpopulation in Malaysia. With these strategies, a practical approach has been identified to overcome the pitfalls posed by the molecular heterogeneity of beta-thalassaemia to enable prenatal diagnosis and carrier screening to be carried out. Regional collaborative studies are to be encouraged as an indispensable tool in providing better health care services to our patients.
    Matched MeSH terms: beta-Thalassemia/diagnosis; beta-Thalassemia/ethnology; beta-Thalassemia/genetics*
  15. Thong MK, Soo TL
    Singapore Med J, 2005 Jul;46(7):340-3.
    PMID: 15968446
    Beta-thalassaemia major is one of the commonest genetic disorders in South East Asia. The strategy for the community control of beta-thalassaemia major requires the characterisation of the spectrum of beta-globin gene mutations in any multi-ethnic population. There is only a single report of mutation analyses of the beta-globin gene in an isolated Kadazandusun community in Kota Belud, Sabah, Malaysia, which showed the presence of a common 45 kb deletion.
    Matched MeSH terms: beta-Thalassemia/ethnology*; beta-Thalassemia/genetics*
  16. Thambiah, S., George, E., Nor Aini, U., Sathar, J., Zarida, H., Mokhtar, A.B.
    MyJurnal
    Management of Beta (β)-thalassaemia intermedia in contrast to β-thalassaemia major patients has no clear guidelines as to indicators of adequate transfusion. Regular blood transfusion suppresses bone marrow erythropoietic activity. Serum soluble transferrin receptor (sTfR) concentration is a marker for erythropoietic activity, with increased sTfR being associated with functional iron deficiency and increased erythropoietic activity. This study aimed to determine the use of sTfR as an indicator of adequate transfusion in adult β-thalassaemia intermedia patients. A cross-sectional study was conducted at Hospital Ampang, Malaysia, for six months. Patient group included six β-thalassaemia intermedia and 34 HbE-β-thalassaemia transfused patients. None of the patients were on regular monthly blood transfusions as in β-thalassaemia major. The control group comprised of 16 healthy subjects with normal haematological parameters. Haemoglobin (Hb) analysis, sTfR and ferritin assays were performed. Hb and HbA percentages (%) were found to be significantly lower in patients compared to the controls, while HbE%, HbF%, sTfR and ferritin were significantly higher in patients. An inverse relationship was found in the controls between HbF% with Hb (r = -0.515, p < 0.05) and HbA% (r = -0.534, p < 0.05). In patients, sTfR showed an inverse relationship with HbA% (r = -0.618, p = 0.000) and a positive correlation with HbE% (r = 0.418, p = 0.007) and HbF% (r = 0.469, p = 0.002). Multivariate analysis showed that HbA% (r = 2.875, p = 0.048), HbE% (r = 2.872, p = 0.020) and HbF% (r = 2.436, p = 0.013) best predicted sTfR independently in patients. Thus, sTfR is a useful marker for erythropoiesis. The elevated sTfR in these patients indicate that the transfusion regimen used was inadequate to suppress ineffective erythropoiesis. Hb levels may not be the best target for monitoring transfusion treatment in β-thalassaemia intermedia patients, but the use of sTfR is helpful in individualising transfusion regimens.
    Matched MeSH terms: beta-Thalassemia
  17. 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-Thalassemia/diagnosis*; beta-Thalassemia/genetics*
  18. 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-Thalassemia/genetics*; beta-Thalassemia/therapy*
  19. Tan KL, Tan JA, Wong YC, Wee YC, Thong MK, Yap SF
    Genet. Test., 2001;5(1):17-22.
    PMID: 11336396 DOI: 10.1089/109065701750168626
    Beta-thalassemia major patients have chronic anemia and are dependent on blood transfusions to sustain life. Molecular characterization and prenatal diagnosis of beta3-thalassemia is essential in Malaysia because about 4.5% of the population are heterozygous carriers for beta-thalassemia. The high percentage of compound heterozygosity (47.62%) found in beta-thalassemia major patients in the Thalassaemia Registry, University of Malaya Medical Centre (UMMC), Malaysia, also supports a need for rapid, economical, and sensitive protocols for the detection of beta-thalassemia mutations. Molecular characterization of beta-thalassemia mutations in Malaysia is currently carried out using ARMS, which detects a single beta-thalassemia mutation per PCR reaction. We developed and evaluated Combine amplification refractory mutation system (C-ARMS) techniques for efficient molecular detection of two to three beta-thalassemia mutations in a single PCR reaction. Three C-ARMS protocols were evaluated and established for molecular characterization of common beta-thalassemia mutations in the Malay and Chinese ethnic groups in Malaysia. Two C-ARMS protocols (cd 41-42/IVSII #654 and -29/cd 71-72) detected the beta-thalassemia mutations in 74.98% of the Chinese patients studied. The CARMS for cd 41-42/IVSII #654 detected beta-thalassemia mutations in 72% of the Chinese families. C-ARMS for cd 41-42/IVSI #5/cd 17 allowed detection of beta-thalassemia mutations in 36.53% of beta-thalassemia in the Malay patients. C-ARMS for cd 41-42/IVSI #5/cd 17 detected beta-thalassemia in 45.54% of the Chinese patients. We conclude that C-ARMS with the ability to detect two to three mutations in a single reaction provides more rapid and cost-effective protocols for beta-thalassemia prenatal diagnosis and molecular analysis programs in Malaysia.
    Matched MeSH terms: beta-Thalassemia/diagnosis*; beta-Thalassemia/genetics*
  20. Tan KK, Lee WS, Liaw LC, Oh A
    Singapore Med J, 1993 Apr;34(2):109-11.
    PMID: 8266145
    Two hundred and eleven blood transfusions were administered to 26 multi-transfused thalassemic children (aged 9 months-13 years) over a 6-month period. Eighteen children were receiving buffy coat-poor packed red cells (PRC) prepared by centrifuge while 8 children received filtered blood through a leucocyte-filter (Sepacell R-500A). Transfusion reactions occurred in 8.5% (n = 18) of transfusions and in 42.3% (n = 11) of patients. 11.9% (n = 16) and 2.6% (n = 2) of reactions occurred in 50% (n = 9) and 25% (n = 2) of patients receiving buffy coat-poor PRC and filtered blood respectively. Transfusion reactions in toto were significantly reduced in the group receiving filtered blood (p < 0.05). However, febrile reaction alone was not significantly reduced (p > 0.1). The median onset and duration of reaction were 2 hours (range 10 minutes-18 hours) and 4 hours (range 1/2-24 hours) respectively. 72.2% (n = 13) of the reactions occurred occurred during transfusion. 88.8% (n = 16) of the reactions caused only one symptom. 19.2% (n = 5) of all patients had recurrent reactions, all of them receiving buffy coat-poor PRC. The commonest clinical manifestation was fever (n = 7), followed by urticaria (n = 5) and petechial rash (n = 2). The outcome was good, with no patient experiencing symptoms exceeding 24 hours. Only 0.9% (n = 2) of the transfusions were discontinued.
    Matched MeSH terms: beta-Thalassemia/therapy*
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