Displaying all 19 publications

Abstract:
Sort:
  1. Kinetic evidence for the occurrence of independent ion-exchange processes in the cationic micellar-mediated reaction of piperidine with anionic phenyl salicylate
    Khan MN, Ismail E
    J Phys Chem A, 2009 Jun 11;113(23):6484-8.
    PMID: 19449852 DOI: 10.1021/jp902886z
    A kinetic probe, which involves the determination of pseudo-first-order rate constants (k(obs)) for the nucleophilic reaction of piperidine (Pip) with ionized phenyl salicylate (S(-)) at constant [Pip](T) (= 0.1 M), [S(-)](T) (= 2 x 10(-4) M), [CTABr](T), < or = 0.10 M NaOH and varying concentration of MX (= 3-ClC(6)H(4)CO(2)Na and C(6)H(5)CH=CHCO(2)Na), gives the following information. The nonlinear plots of k(obs) versus [MX] reveal indirectly the occurrence of more than one independent ion-exchange processes at the CTABr micellar surface. These observed data fit to a kinetic relationship derived from an empirical equation coupled with pseudophase micellar (PM) model. This relationship gives an empirical constant (K(X/S)) that is used to determine the usual ion-exchange constant (K(X)(Y)). The values of K(X)(Br) (Y = Br) have been calculated for X = 3-ClC(6)H(4)CO(2)(-) and C(6)H(5)CH=CHCO(2)(-). More than 12-fold larger value of K(X)(Br) for X = 3-ClC(6)H(4)CO(2)(-) than that for X = 2-ClC(6)H(4)CO(2)(-) is attributed to the presence and absence of viscoelasticity in the respective presence of 3-ClC(6)H(4)CO(2)(-) and 2-ClC(6)H(4)CO(2)(-).
  2. Genetic variability of wild horseshoe crabs (Tachypleus gigas) from west coast of Peninsular Malaysia
    Rozihan M, Ismail E, Akbar John B
    Commun. Agric. Appl. Biol. Sci., 2013;78(4):399-402.
    PMID: 25141724
  3. 3'-UTR variations and G6PD deficiency
    Amini F, Ismail E
    J Hum Genet, 2013 Apr;58(4):189-94.
    PMID: 23389243 DOI: 10.1038/jhg.2012.155
    The combination of two silent mutations, c.1311C>T in exon 11 and IVS11 T93C (glucose-6-phosphate dehydrogenase (G6PD) 1311T/93C), with unknown mechanism, have been reported in G6PD-deficient individuals in Asian populations including Malaysian aboriginal group, Negrito. Here, we report the screening of G6PD gene in 103 Negrito volunteers using denaturing high-performance liquid chromatography (dHPLC) and direct sequencing. A total of 48 individuals (46.6%) were G6PD deficient, 83.3% of these carried G6PD 1311T/93C with enzyme activity ranging from 1.8 to 4.8 U gHb(-1). Three novel single-nucleotide polymorphisms (SNPs), rs112950723, rs111485003 and rs1050757, were found in the G6PD 3'-untranslated region (UTR). Strong association was observed between haplotype 1311T/93C and rs1050757G, which is located inside the 35 bp AG-rich region. In silico analysis revealed that the transition of A to G at position rs1050757 makes significant changes in the G6PD mRNA secondary structure. Moreover, putative micro (mi)RNA target sites were identified in 3'-UTR of G6PD gene, two of these in the region encompassing rs1050757. It could be speculated that rs1050757 have a potential functional effect on the downregulation of mRNA and consequently G6PD deficiency either by affecting mRNA stability and translation or mirRNA regulation process. This is the first report of biochemical association of an SNP in 3'-UTR of G6PD gene and the possible role of mRNA secondary structure.
  4. Effects of Nonionic and Mixed Cationic-Nonionic Micelles on the Rate of Alkaline Hydrolysis of 4-Nitrophthalimide
    Khan MN, Ismail E
    J Colloid Interface Sci, 2001 Aug 15;240(2):636-639.
    PMID: 11482975
    Pseudo-first-order rate constants (k(obs)) for alkaline hydrolysis of 4-nitrophthalimide show a monotonic decrease with increase in [C(12)E(23)](T) (total concentration of Brij 35) at constant [CH(3)CN] and [NaOH]. This micellar effect is explained in terms of a pseudophase micelle model. The rate of hydrolysis becomes too slow to monitor at [C(12)E(23)](T)>/=0.03 M in the absence of cetyltrimethylammonium bromide (CTABr) and at [C(12)E(23)](T)>/=0.04 M in the presence of 0.006-0.02 M CTABr at 0.01 M NaOH. The plots of k(obs) versus [C(12)E(23)](T) show minima at 0.006 and 0.01 M CTABr, while such a minimum is not visible at 0.02 M CTABr. Copyright 2001 Academic Press.
  5. Effects of Nonionic, Cationic, and Mixed Nonionic-Cationic Surfactants on the Acid-Base Behavior of Phenyl Salicylate
    Khan MN, Arifin Z, Yusoff MR, Ismail E
    J Colloid Interface Sci, 1999 Dec 15;220(2):474-476.
    PMID: 10607470
    The effects of Brij 35 micelles, CTABr micelles, and mixed Brij 35-CTABr micelles on the acid-base behavior of phenyl salicylate (PST) have been studied in aqueous solution containing 2% v/v acetonitrile. The apparent pK(b) (pK(app)(b)) of PST is decreased by 1.5 pK units with the increase in [Brij 35] from 0 to 0.02 M which is attributed to micellar medium effect. The values of pK(app)(b) remain almost independent of [CTABr] within its range 0.01-0.03 M. The increase in [CTABr] from 0 to 0.03 M in aqueous solution containing 0.02 M Brij 35 has not resulted in a change in pK(app)(b). This shows that the characeristic structural features of nonionic Brij 35 micelles remain essentially unchanged on addition of CTABr under the present experimental conditions. Copyright 1999 Academic Press.
  6. Effects of
    Khan MN, Arifin Z, Ismail E, Ali SF
    J Org Chem, 2000 Mar 10;65(5):1331-4.
    PMID: 10814092
    Effects of cetyltrimethylammonium bromide (CTABr) micelles on second-order rate constants (k(n)(obs)) for nucleophilic reactions of amines (piperidine and n-butylamine) with ionized phenyl salicylate (PS(-)) reveal a nonlinear decrease with the increase in [D(n)] (where [D(n)] = [CTABr](T) - cmc) at a constant [NaBr] and 35 degrees C. The observed data, at a constant [NaBr], fit reasonably well to a pseudophase model of micelles, and such a data fit gives kinetic parameters such as CTABr micellar binding canstant (K(S)) of PS(-). The effect of [NaBr] upon K(S) is explained with the empirical relationship K(S) = K(S)(0)/(1 + psi[NaBr]), where psi is an empirical parameter.
  7. Prevalence and molecular study of G6PD deficiency in Malaysian Orang Asli
    Amini F, Ismail E, Zilfalil BA
    Intern Med J, 2011 Apr;41(4):351-3.
    PMID: 21507164 DOI: 10.1111/j.1445-5994.2011.02456.x
    This study aims to define the prevalence and the molecular basis of G6PD deficiency in the Negrito tribe of the Malaysian Orang Asli. Four hundred and eighty seven consenting Negrito volunteers were screened for G6PD deficiency through the use of a fluorescent spot test. DNA from deficient individuals underwent PCR-RFLP analysis using thirteen recognized G6PD mutations. In the instances when the mutation could not be identified by PCR-RFLP, the entire coding region of the G6PD gene was subjected to DNA sequencing. In total, 9% (44/486) of the sample were found to be G6PD-deficient. However, only 25 samples were subjected to PCR-RFLP and DNA sequencing. Of these, three were found to carry Viangchan, one Coimbra and 16, a combination of C1311T in exon 11 and IVS11 T93C. Mutation(s) for the five remaining samples are unknown. The mean G6PD enzyme activity ranged 5.7 IU/gHb in deficient individuals. Our results demonstrate that the frequency of G6PD deficiency is higher among the Negrito Orang Asli than other Malaysian races. The dual presence of C1311T and IVS11 T93C in 64% of the deficient individuals (16/44) could well be a result of genetic drift within this isolated group.
  8. Fulltext Epidemiology of dengue disease in Malaysia (2000-2012): a systematic literature review
    Mohd-Zaki AH, Brett J, Ismail E, L'Azou M
    PLoS Negl Trop Dis, 2014;8(11):e3159.
    PMID: 25375211 DOI: 10.1371/journal.pntd.0003159
    A literature survey and analysis was conducted to describe the epidemiology of dengue disease in Malaysia between 2000 and 2012. Published literature was searched for epidemiological studies of dengue disease, using specific search strategies for each electronic database; 237 relevant data sources were identified, 28 of which fulfilled the inclusion criteria. The epidemiology of dengue disease in Malaysia was characterized by a non-linear increase in the number of reported cases from 7,103 in 2000 to 46,171 in 2010, and a shift in the age range predominance from children toward adults. The overall increase in dengue disease was accompanied by a rise in the number, but not the proportion, of severe cases. The dominant circulating dengue virus serotypes changed continually over the decade and differed between states. Several gaps in epidemiological knowledge were identified; in particular, studies of regional differences, age-stratified seroprevalence, and hospital admissions.

    PROTOCOL REGISTRATION: PROSPERO #CRD42012002293.

  9. Fulltext The clinical significance of interleukin-1 receptor antagonist +2018 polymorphism in rheumatoid arthritis
    Ismail E, Nofal OK, Sakthiswary R, Shaharir SS, Sridharan R
    PLoS One, 2016;11(4):e0153752.
    PMID: 27105431 DOI: 10.1371/journal.pone.0153752
    OBJECTIVE: Interleukin-1 receptor antagonist (IL-1Ra) acts as an inhibitor of IL-1; which is one of the culprit cytokines in rheumatoid arthritis (RA). Although +2018 polymorphism of IL-1Ra has been implicated in the pathogenesis of RA, its importance remains poorly understood. Hence, the purpose of this study was to determine the clinical significance of interleukin-1 receptor antagonist (IL-1Ra) +2018 polymorphism in RA.
    METHODS: Polymerase chain reaction (PCR) and sequencing were used to determine the genotypes of the IL-1Ra +2018 for 77 RA patients and 18 healthy controls. All RA patients were assessed for the disease activity score that includes 28 joints (DAS28) and radiographic disease damage based on Modified Sharp Score (MSS).
    RESULTS: The frequency of the T/T and C/T genotypes did not differ significantly (p = 0.893) between the RA patients and the controls. The C/T genotype had significantly higher mean disease activity (DAS 28) and disease damage (MSS) scores with p values of 0.017 and 0.004, respectively. Additionally, the ESR (erythrocyte sedimentation rate), CRP (C-reactive protein), the number of swollen and tender joints were higher for the C/T individuals. On multivariate analysis the CRP, swollen joint count and MSS remained significant with the following p values i.e. 0.045, 0.046 and less than 0.05.
    CONCLUSIONS: C/T genotype of IL-1Ra +2018 prognosticates more aggressive disease in RA.
    Study site: Outpatient clinic, Pusat Perubatan Universiti Kebangsaan Malaysia (PPUKM), Kuala Lumpur, Malaysia
  10. Fulltext Peninsular Malaysia’s Negrito orang asli and its theory of African origin
    Ismail E, Amini F, Abdul Razak S, Mohd Zaini H, Alwi Z, Farhour R
    Sains Malaysiana, 2013;42:921-926.
    Negritos of Peninsular Malaysia have physical features which strongly resemble the African pygmies rather than any of the other main South East Asian ethnic groups. In addition, their features are also completely different from the two other large sub-groups of the Peninsular Malaysia Orang Asli, i.e. Senoi and Proto-Malay. In this study, we genetically screened three African-specific markers, Glucose-6 Phosphate Dehydrogenase (G6PD) gene PvuII Type 2 polymorphism and A- mutation; and Sickle Cell trait in 103 unrelated individuals with G6PD deficiency. None of the Negritos’ samples carried A- and Sickle cell mutations but all males and females have the PvuII Type 2 polymorphism. The same results were seen in all DNA samples of the Malaysian’s Malay, Chinese and Indians. Additionally, all females in this study were homozygous for PvuII Type 2 polymorphism. Thus, we concluded that this polymorphism is widespread in all Malaysian population and is not unique to just Africans. However, these findings indicated that the polymorphism was widely conserved and can be used to study the African descendant in any world population hitherto supporting the ‘Out of Africa’ theory.
  11. Fulltext Population screening for glucose-6-phosphate dehydrogenase deficiency using quantitative point-of-care tests: a systematic review
    Zailani MAH, Raja Sabudin RZA, Ithnin A, Alauddin H, Sulaiman SA, Ismail E, et al.
    Front Genet, 2023;14:1098828.
    PMID: 37388931 DOI: 10.3389/fgene.2023.1098828
    Background: Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an X-linked hereditary disorder and a global public health concern that is most prevalent in malaria-endemic regions including Asia, Africa, and the Mediterranean. G6PD-deficient individuals are at high risk of developing acute hemolytic anemia following treatment with antimalarial drugs including Primaquine and Tafenoquine. However, the currently available tests for G6PD screening are complex and often have been misclassifying cases, particularly for females with intermediate G6PD activity. The latest innovation of quantitative point-of-care (POC) tests for G6PD deficiency provides an opportunity to improve population screening and prevent hemolytic disorders when treating malaria. Aim(s): To assess the evidence on the type and performance of quantitative point-of-care (POC) tests for effective G6PD screening and hence, radical elimination of Plasmodium malaria infections. Methods: Relevant studies published in English language confined from two databases, Scopus and ScienceDirect were searched from November 2016 onwards. The search was conducted using keywords including "glucosephosphate dehydrogenase" or "G6PD", "point-of-care", "screening" or "prevalence", "biosensor" and "quantitative". The review was reported following the PRISMA guidelines. Results: Initial search results yielded 120 publications. After thorough screening and examination, a total of 7 studies met the inclusion criteria, and data were extracted in this review. Two types of quantitative POC tests were evaluated, namely, the CareStartTM Biosensor kit and the STANDARD G6PD kit. Both tests showed promising performance with high sensitivity and specificity ranging mostly from 72% to 100% and 92%-100%, respectively. The positive and negative predictive values (PPV and NPV) ranged from 35% to 72% and 89%-100%, with accuracy ranging from 86% to 98%. Conclusion: In areas with a high prevalence of G6PD deficiency that overlap with malaria endemicity, availability and validation of the diagnostic performance of quantitative POC tests are of absolute importance. Carestart™ biosensor and STANDARD G6PD kits showed high reliability and performed well in comparison to the spectrophotometric reference standard.
  12. Fulltext Anopheles sundaicus  complex and the presence of Anopheles epiroticus in Indonesia
    Syafruddin D, Lestari YE, Permana DH, Asih PBS, St Laurent B, Zubaidah S, et al.
    PLoS Negl Trop Dis, 2020 Jul;14(7):e0008385.
    PMID: 32614914 DOI: 10.1371/journal.pntd.0008385
    Anopheles sundaicus s.l. is an important malaria vector primarily found in coastal landscapes of western and central Indonesia. The species complex has a wide geographical distribution in South and Southeast Asia and exhibits ecological and behavioural variability over its range. Studies on understanding the distribution of different members in the complex and their bionomics related to malaria transmission might be important guiding more effective vector intervention strategies. Female An. sundaicus s.l. were collected from seven provinces, 12 locations in Indonesia representing Sumatra: North Sumatra, Bangka-Belitung, South Lampung, and Bengkulu; in Java: West Java; and the Lesser Sunda Islands: West Nusa Tenggara and East Nusa Tenggara provinces. Sequencing of ribosomal DNA ITS2 gene fragments and two mitochondrial DNA gene markers, COI and cytb, enabled molecular identification of morphologically indistinguishable members of the complex. Findings allowed inference on the distribution of the An. sundaicus s.l. present in Indonesia and further illustrate the phylogenetic relationships of An. epiroticus within the complex. A total of 370 An. sundaicus s.l specimens were analysed for the ITS2 fragment. The ITS2 sequence alignment revealed two consistent species-specific point mutations, a T>C transition at base 479 and a G>T transversion at base 538 that differentiated five haplotypes: TG, CG, TT, CT, and TY. The TG haplotype matched published An. epiroticus-indicative sequences from Thailand, Vietnam and peninsular Malaysia. The previously described insertion event (base 603) was observed in all identified specimens. Analysis of the COI and cytb genes revealed no consistent nucleotide variations that could definitively distinguish An. epiroticus from other members in the Sundaicus Complex. The findings indicate and support the existence of An. epiroticus in North Sumatra and Bangka-Belitung archipelago. Further studies are recommended to determine the full distributional extent of the Sundaicus complex in Indonesia and investigate the role of these species in malaria transmission.
  13. Fulltext Dermatoglyphics: comparison between Negritos Orang Asli and the Malays, Chinese and Indian
    Ismail E, Abdul Razak S, Selamat L, Gurusamy R, Zariman H, Shahrudin MS, et al.
    Sains Malaysiana, 2009 6;38:947-952.
    Dermatoglyphic traits are formed under genetic control during early gestation and do not change through the entire life. A few studies have shown that dermatoglyphic traits were conservative in their evolution and were different between and within population groups. The objective of this study was to compare the variability of palm dermatoglyphs in three main populations i.e. Malay, Chinese, Indian and five sub-ethnic population of Negritos’ Orang Asli i.e. Bateq, Jahai, Kintak, Kensiu and Lanoh. We utilised fingerprints and palms of 390 healthy adult individuals, counted the total ridge for ten fingers
    (TRC), a-b ridge counts (a-b RC) on palms, examined widening of the atd-angle, and classified the digital pattern configuration of arches, whorls, ulnar, and radial loops for all fingers. Variables obtained from both palm did not show any differences between males and females for all populations. TRC, a-b RC and atd-angle were the highest for Kensiu and were later on specially described to be in a group of its own by ANOVA and TUKEY test for TRC and a-b RC. The same test has put Chinese in a group of its own for atd-angle. Only a-b RC clearly separate Orang Asli populations from the three main races. Whorls and ulnar loops were the most predominant pattern in all groups. Malays and Chinese had similar distributional patterns for each ten fingers. Indian and Jahai similarly mimic each other, while Bateq has the reversal pattern distribution to them both. Kintak and Lanoh halfly mimics each other pattern and Kensiu had its own unique pattern. In conclusion, races, patterns, and pattern frequencies were related to each other and can be used to differentiate different races or Orang Asli
    sub-ethnics. This study documents for the first time the comparative dermatoglyphic traits between Malaysian main races with Orang Asli populations show a list of informative variables that can be used to identify them as well as suggesting it’s used as a tool in tracing the etnohistorical background of populations.
  14. The role of gas-phase dynamics in interfacial phenomena during few-layer graphene growth through atmospheric pressure chemical vapour deposition
    Fauzi FB, Ismail E, Syed Abu Bakar SN, Ismail AF, Mohamed MA, Md Din MF, et al.
    Phys Chem Chem Phys, 2020 Feb 12;22(6):3481-3489.
    PMID: 31989130 DOI: 10.1039/c9cp05346h
    The complicated chemical vapour deposition (CVD) is currently the most viable method of producing graphene. Most studies have extensively focused on chemical aspects either through experiments or computational studies. However, gas-phase dynamics in CVD reportedly plays an important role in improving graphene quality. Given that mass transport is the rate-limiting step for graphene deposition in atmospheric-pressure CVD (APCVD), the interfacial phenomena at the gas-solid interface (i.e., the boundary layer) are a crucial controlling factor. Accordingly, only by understanding and controlling the boundary-layer thickness can uniform full-coverage graphene deposition be achieved. In this study, a simplified computational fluid dynamics analysis of APCVD was performed to investigate gas-phase dynamics during deposition. Boundary-layer thickness was also estimated through the development of a customised homogeneous gas model. Interfacial phenomena, particularly the boundary layer and mass transport within it, were studied. The effects of Reynolds number on these factors were explored and compared with experimentally obtained results of the characterised graphene deposit. We then discussed and elucidated the important relation of fluid dynamics to graphene growth through APCVD.
  15. Molecular Characterisation of α- and β-Thalassaemia among Indigenous Senoi Orang Asli Communities in Peninsular Malaysia
    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 ).
  16. 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.
  17. The population genomic landscape of human genetic structure, admixture history and local adaptation in Peninsular Malaysia
    Deng L, Hoh BP, Lu D, Fu R, Phipps ME, Li S, et al.
    Hum Genet, 2014 Sep;133(9):1169-85.
    PMID: 24916469 DOI: 10.1007/s00439-014-1459-8
    Peninsular Malaysia is a strategic region which might have played an important role in the initial peopling and subsequent human migrations in Asia. However, the genetic diversity and history of human populations--especially indigenous populations--inhabiting this area remain poorly understood. Here, we conducted a genome-wide study using over 900,000 single nucleotide polymorphisms (SNPs) in four major Malaysian ethnic groups (MEGs; Malay, Proto-Malay, Senoi and Negrito), and made comparisons of 17 world-wide populations. Our data revealed that Peninsular Malaysia has greater genetic diversity corresponding to its role as a contact zone of both early and recent human migrations in Asia. However, each single Orang Asli (indigenous) group was less diverse with a smaller effective population size (N(e)) than a European or an East Asian population, indicating a substantial isolation of some duration for these groups. All four MEGs were genetically more similar to Asian populations than to other continental groups, and the divergence time between MEGs and East Asian populations (12,000--6,000 years ago) was also much shorter than that between East Asians and Europeans. Thus, Malaysian Orang Asli groups, despite their significantly different features, may share a common origin with the other Asian groups. Nevertheless, we identified traces of recent gene flow from non-Asians to MEGs. Finally, natural selection signatures were detected in a batch of genes associated with immune response, human height, skin pigmentation, hair and facial morphology and blood pressure in MEGs. Notable examples include SYN3 which is associated with human height in all Orang Asli groups, a height-related gene (PNPT1) and two blood pressure-related genes (CDH13 and PAX5) in Negritos. We conclude that a long isolation period, subsequent gene flow and local adaptations have jointly shaped the genetic architectures of MEGs, and this study provides insight into the peopling and human migration history in Southeast Asia.
  18. Fulltext Multiplex amplification refractory mutation system (MARMS) for the detection of β-globin gene mutations among the transfusion-dependent β-thalassemia Malay patients in Kelantan, Northeast of Peninsular Malaysia
    Hanafi S, Hassan R, Bahar R, Abdullah WZ, Johan MF, Rashid ND, et al.
    Am J Blood Res, 2014;4(1):33-40.
    PMID: 25232503
    The aim of this study was to adapt MARMS with some modifications to detect beta mutation in our cohort of thalassemia patients. We focused only on transfusion-dependent thalassemia Malay patients, the predominant ethnic group (95%) in the Kelantanese population. Eight mutations were identified in 46 out of 48 (95.83%) beta thalassemia alleles. Most of the patients (54.2%) were compound heterozygous with co-inheritance Cd 26 (G>A). The frequencies of spectrum beta chain mutation among these patients are presented in Table 2. Among the transfusion dependent beta thalassemia Malay patients studied, 26 patients were found to be compound heterozygous and the main alleles were Cd 26 (G>A). Compound heterozygous mutation of Cd 26 (G>A) and IVS 1-5 (G>C) were 12 (46.2%), Cd 26 (G>A) and Cd 41/42 (TTCT) were 9 (34.6%), Cd 26 (G>A) and IVS 1-1 (G>C) were 2 (7.7%) respectively. Meanwhile the minority were made of a single compound heterozygous of Cd 26 (G>A) and Cd 71/72, Cd 26 (>A) and Cd 17 (A>T), Cd 26 (G>A) and -28 (G>A) respectively. Twenty out of forty six patients were shown to have homozygous of IVS 1-5 (G>C) were 2 (10.0%), Cd 26 (G>A) were 15 (75.0%), Cd 19 (A>G) were 1 (5.0%), and IVS 1-1 (G>T) were 2 (10.0%). The beta chain mutations among the Kelantanese Malays followed closely the distribution of beta chain mutations among the Thais and the Malays of the Southern Thailand. The G-C transition at position 5 of the IVS 1-5 mutation was predominant among the Malay patients. In conclusion, this method has successfully identified the mutation spectrum in our cohort of transfusion-dependent beta thalassemia patients, and this method is equally effective in screening for mutation among thalassemia patients.
  19. Fulltext The first Malay database toward the ethnic-specific target molecular variation
    Halim-Fikri H, Etemad A, Abdul Latif AZ, Merican AF, Baig AA, Annuar AA, et al.
    BMC Res Notes, 2015;8:176.
    PMID: 25925844 DOI: 10.1186/s13104-015-1123-y
    The Malaysian Node of the Human Variome Project (MyHVP) is one of the eighteen official Human Variome Project (HVP) country-specific nodes. Since its inception in 9(th) October 2010, MyHVP has attracted the significant number of Malaysian clinicians and researchers to participate and contribute their data to this project. MyHVP also act as the center of coordination for genotypic and phenotypic variation studies of the Malaysian population. A specialized database was developed to store and manage the data based on genetic variations which also associated with health and disease of Malaysian ethnic groups. This ethnic-specific database is called the Malaysian Node of the Human Variome Project database (MyHVPDb).
Related Terms
    Try searching for something
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links