Displaying publications 1 - 20 of 176 in total

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  1. Tan JAMA, Yap SF, Tan KL, Wong YC, Wee YC, Kok JL
    Acta Haematol., 2003;109(4):169-75.
    PMID: 12853688 DOI: 10.1159/000070965
    Molecular characterization of the compound heterozygous condition - (G)gamma((A)gammadeltabeta)(o)/beta-thalassemia - in four families showing mild beta-thalassemia intermedia was carried out using DNA amplification techniques. Using the Amplification Refractory Mutation System (ARMS) to confirm the beta-mutations and DNA amplification to detect the 100-kb Chinese-specific (G)gamma((A)gammadeltabeta)(o)-deletion, ()two families were confirmed to possess (G)gamma((A)gammadeltabeta)(o)/beta-thalassemia with the IVSII No. 654 beta(+)-allele. In the third family, the (G)gamma((A)gammadeltabeta)(o)-deletion was confirmed in the father and the mother was a beta-thalassemia carrier with the cd 41-42 beta(o)-allele. Their affected child with (G)gamma((A)gammadeltabeta)(o)/beta-thalassemia was found to be transfusion dependent. The same (G)gamma((A)gammadeltabeta)(o)-deletion and beta-thalassemia (cd 41-42) was also confirmed in a fourth family. In addition, the mother was also diagnosed with Hb H disease (genotype -alpha(3.7)/-(SEA)). Both the children were found to possess (G)gamma((A)gammadeltabeta)(o)/beta-thalassemia but they were not transfusion dependent and this could be due to co-inheritance of alpha-thalassemia-2 (genotype-alpha(3.7)/alphaalpha) in the children together with their compound heterozygous condition.
    Matched MeSH terms: Polymorphism, Restriction Fragment Length
  2. Bamaga OA, Mahdy MA, Lim YA
    Acta Trop, 2015 Sep;149:59-63.
    PMID: 26001972 DOI: 10.1016/j.actatropica.2015.05.013
    Malaria is still a major public health problem in Yemen. More than 95% of the malaria cases are due to Plasmodium ‎falciparum‎. Recently in Yemen, the antimalarial treatment policy was changed from chloroquine (CQ) to artemisinin combination therapy (ACTs). However, CQ is still available and prescribed in the Yemeni market. The persistence of CQ resistance will be prolonged if the shift to ACT and the simultaneous withdrawal of CQ are not rigorously implemented. The aim of the current survey is to detect chloroquine-resistant mutations in P. falciparum chloroquine-resistance transporter (pfcrt) and P. falciparum multi-drug resistance-1 (pfmdr1) genes. These data will be important for future monitoring and assessment of antimalarial drug policy in Yemen. Blood specimens were collected from 735 individuals from different districts of the Hadhramout province, Yemen by house-to-house visit. Mutation-specific nested polymerase chain reaction (PCR) and restriction fragment length polymorphism (PCR-RFLP) methods were used to investigate the mutations in the pfmdr1(codons 86 and 1246) and pfcrt (codons 76, 271, 326, 356 and 371) genes. The overall prevalence of pfcrt mutations at codons 76, 271, 326 and 371 were 50.4%, 58.7%, 54.3% and 44.9%, respectively. All isolates had wild-type pfcrt 356 allele. The majority of pfmdr1 86 alleles (83.3%) and all pfmdr1 1246 alleles were wild type. There was no association between pfcrt mutations and symptomatology, gender and age groups. In conclusion, point mutations in codons 76, 271, 326 and 371 of pfcrt of P. falciparum are high suggesting a sustained high CQ resistance even after 4 years of shifting to ACTs. These findings warrant complete withdrawal of CQ use from the Yemeni market for P. falciparum and careful usage of CQ for treating Plasmodium vivax.
    Matched MeSH terms: Polymorphism, Restriction Fragment Length
  3. Alareqi LMQ, Mahdy MAK, Lau YL, Fong MY, Abdul-Ghani R, Mahmud R
    Acta Trop, 2016 Oct;162:174-179.
    PMID: 27343362 DOI: 10.1016/j.actatropica.2016.06.016
    Since 2005, artesunate (AS) plus sulfadoxine/pyrimethamine (SP) combination has been adopted as the first-line treatment for uncomplicated malaria in Yemen in response to the high level of Plasmodium falciparum resistance to chloroquine (CQ). Therefore, the aim of the present study was to determine the frequency distribution of molecular markers associated with resistance to CQ and AS plus SP combination among P. falciparum isolates from a malaria-endemic area in Taiz governorate, Yemen. Fifty P. falciparum isolates were collected during a cross-sectional study in Mawza district, Taiz, in the period from October 2013 to April 2014. The isolates were investigated for drug resistance-associated molecular markers in five genes, including P. falciparum CQ resistance transporter (pfcrt) 76T and P. falciparum multidrug resistance 1 (pfmdr1) 86Y as markers of resistance to CQ, mutations in the Kelch 13 (K13) propeller domain for resistance to AS, and P. falciparum dihydrofolate reductase (pfdhfr) and P. falciparum dihydropteroate synthase (pfdhps) genes for resistance to SP. Nested polymerase chain reaction was used to amplify target genes in DNA extracts of the isolates followed by restriction fragment length polymorphism for detecting 76T and 86Y mutations in pfcrt and pfmdr1, respectively, and by DNA sequencing for detecting mutations in K13, pfdhfr and pfdhps. All the investigated isolates from Mawza district were harboring the pfcrt 76T mutant and the pfmdr1 N86 wild-type alleles. The pfdhfr 51I/108N double mutant allele was found in 2.2% (1/45) of the isolates; however, no mutations were detected at codons 436, 437, 540, 581 and 613 of pfdhps. All P. falciparum isolates that were successfully sequenced (n=47) showed the K13 Y493, R539, I543 and C580 wild-type alleles. In conclusion, the pfcrt 76T mutant allele is fixed in the study area about six years after the official withdrawal of CQ, possibly indicating its over-the-counter availability and continued use as a self-medication in the study area. However, the almost predominant wild-type alleles of the genes associated with resistance to AS and SP among P. falciparum isolates in the present study indicates the sustained efficacy of the currently adopted first-line treatment of AS plus SP in the study area.
    Matched MeSH terms: Polymorphism, Restriction Fragment Length
  4. Shmukler BE, Kedar PS, Warang P, Desai M, Madkaikar M, Ghosh K, et al.
    Am J Hematol, 2010 Oct;85(10):824-8.
    PMID: 20799361 DOI: 10.1002/ajh.21836
    Familial distal renal tubular acidosis (dRTA) can be caused by mutations in the Cl2/HCO32 exchanger of the renal Type A intercalated cell, kidney AE1/SLC4A1. dRTA-associated AE1 mutations have been reported in families from North America, Europe, Thailand, Malaysia, Papua-New Guinea, Taiwan, and the Philippines, but not India. The dRTA mutation AE1 A858D has been detected only in the context of compound heterozygosity. We report here two unrelated Indian patients with combined hemolytic anemia and dRTA who share homozygous A858D mutations of the AE1/SLC4A1 gene. The mutation creates a novel restriction site that is validated for diagnostic screening.
    Matched MeSH terms: Polymorphism, Restriction Fragment Length
  5. Chua KH, Puah SM, Chew CH, Tan SY, Lian LH
    Ann Hum Biol, 2010 Apr;37(2):274-80.
    PMID: 19951233 DOI: 10.3109/03014460903325185
    In this study, we investigated the polymorphisms of the exon 1 (+49A/G), promoter sites (-1722T/C, -1661A/G, -318C/T), and 3'-untranslated region (3'-UTR) (+6230 A/G) of the CTLA-4 gene in systemic lupus erythematosus (SLE) affected patients. Polymerase chain reaction-restriction fragment length polymorphism was used to determine genotypes of these five markers in 130 SLE patients and 130 healthy controls. Of the five tested polymorphisms, there was no statistical significant difference between the genotypic and allelic frequencies of patients with SLE and controls. Hence, we propose that the CTLA-4 gene does not play a major role in the genetic susceptibility to the development of SLE in the Malaysian population.
    Matched MeSH terms: Polymorphism, Restriction Fragment Length
  6. Thong KL, Cordano AM, Yassin RM, Pang T
    Appl Environ Microbiol, 1996 Jan;62(1):271-4.
    PMID: 8572705
    Molecular characterization of a total of 54 isolates of Salmonella typhi from Santiago, Chile, was performed by pulsed-field gel electrophoresis (PFGE) after digestion of chromosomal DNA with three restriction endonucleases: XbaI (5'-TCTAGA-3'), AvrII (5'-CCTAGG-3'), and SpeI (5'-ACTAGT-3'). Thirteen of the 54 isolates were obtained from environmental sources (sewage and river water), and the rest were isolates from clinical cases of typhoid fever. Considerable genetic diversity was detected among the human isolates obtained in 1994, as evidenced by the presence of 14 to 19 different PFGE patterns among 20 human isolates, with F (coefficient of similarity) values ranging from 0.69 to 1.0 (XbaI), 0.61 to 1.0 (AvrII), and 0.70 to 1.0 (SpeI). A total of eight phage types were detected among these 20 isolates, with 50% possessing the E1 or 46 phage type. There was no correlation between PFGE pattern and phage types. Similar diversity was seen among 21 isolates obtained in 1983, with 17 to 19 PFGE patterns detected and F values of 0.56 to 1.0 (XbaI), 0.55 to 1.0 (AvrII), and 0.67 to 1.0 (SpeI). Comparison of these two groups of human isolates obtained 11 years apart indicated that certain molecular types of S. typhi are shared and are able to persist for considerable periods. A similar degree of genetic diversity was also detected among the environmental isolates of S. typhi, for which 10 to 12 different PFGE patterns were detected among the 13 isolates analyzed, with F values ranging from 0.56 to 1.0 (XbaI), 0.52 to 1.0 (AvrII), and 0.69 to 1.0 (SpeI). Certain molecular types present among the environmental isolates of S. typhi were also found among the human isolates from the same time period, providing evidence for the epidemiological link between environmental reservoirs and human infection.
    Matched MeSH terms: Polymorphism, Restriction Fragment Length*
  7. Adhikari TB, Cruz C, Zhang Q, Nelson RJ, Skinner DZ, Mew TW, et al.
    Appl Environ Microbiol, 1995 Mar;61(3):966-71.
    PMID: 16534980
    Restriction fragment length polymorphism and virulence analyses were used to evaluate the population structure of Xanthomonas oryzae pv. oryzae, the rice bacterial blight pathogen, from several rice-growing countries in Asia. Two DNA sequences from X. oryzae pv. oryzae, IS1112, an insertion sequence, and avrXa10, a member of a family of avirulence genes, were used as probes to analyze the genomes of 308 strains of X. oryzae pv. oryzae collected from China, India, Indonesia, Korea, Malaysia, Nepal, and the Philippines. On the basis of the consensus of three clustering statistics, the collection formed five clusters. Genetic distances within the five clusters ranged from 0.16 to 0.51, and distances between clusters ranged from 0.48 to 0.64. Three of the five clusters consisted of strains from a single country. Strains within two clusters, however, were found in more than one country, suggesting patterns of movement of the pathogen. The pathotype of X. oryzae pv. oryzae was determined for 226 strains by inoculating five rice differential cultivars. More than one pathotype was associated with each cluster; however, some pathotypes were associated with only one cluster. Most strains from South Asia (Nepal and India) were virulent to cultivars containing the bacterial blight resistance gene xa-5, while most strains from other countries were avirulent to xa-5. The regional differentiation of clusters of X. oryzae pv. oryzae in Asia and the association of some pathotypes of X. oryzae pv. oryzae with single clusters suggested that strategies that target regional resistance breeding and gene deployment are feasible.
    Matched MeSH terms: Polymorphism, Restriction Fragment Length
  8. Eshkoor SA, Ismail P, Rahman SA, Moin S
    Arh Hig Rada Toksikol, 2011 Dec;62(4):291-8.
    PMID: 22202462 DOI: 10.2478/10004-1254-62-2011-2088
    The aim of our study was to see the effects of GSTP1 polymorphism on biomarkers of ageing, including micronuclei (MN), comet tail length, and relative telomere length in automobile repair workers, who are exposed to a broad spectrum of potential mutagens. The analysis was performed on buccal cells collected from occupationally exposed and non-exposed (control) subjects. Samples were analysed using cytogenetic and molecular methods, including restriction fragment length polymorphism (RFLP), MN test, comet assay, and real-time PCR. The results confirmed the DNA damaging effects of substances used in the mechanical workshops, but did not confirm the influence of GSTP1 gene polymorphism on DNA damage. However, further studies on both occupationally exposed and control populations are needed to understand the relationship between GSTP1 polymorphism and genome damage.
    Matched MeSH terms: Polymorphism, Restriction Fragment Length
  9. Mohamad S, Hamid SSA, Azlina A, Md Shukri N
    Asia Pac Allergy, 2019 Jul;9(3):e22.
    PMID: 31384577 DOI: 10.5415/apallergy.2019.9.e22
    Background: Chronic rhinosinusitis (CRS) is one of the most common and complex chronic inflammatory disease of sinonasal mucosa. Even though the pathogenesis of CRS is multifactorial and still unclear, the role of cytokines especially interleukin-1 (IL-1) is being investigated worldwide in different population because of varying results obtained.

    Objective: To study the association of IL-1 (A and B) gene polymorphisms with chronic rhinosinusitis with nasal polyp (CRSwNP) and without nasal polyp (CRSsNP), and other factors related.

    Methods: This is a case-controlled study which include a total of 138 subjects recruited from Otorhinolaryngology-Head and Neck Surgery clinic in Hospital Universiti Sains Malaysia. Genotyping of the IL-1A (+4845G, +4845T) and IL-1B (-511C, -511T) were performed with restriction fragment length polymorphism analysis.

    Results: There was a statistical significant association between IL-1B (-511C, -511T) polymorphism with CRSwNP and CRSsNP (p < 0.001). The CT genotype of IL-1B was markedly increased in CRSwNP subjects (52.2%). However, there was no significant association found between IL-1A (+4845G, +4845T) with CRSwNP and CRSsNP (p = 0.093). No association was found in factors related to CRS, which included asthma, atopy, allergy, aspirin sensitivity, and family history of nasal polyp (p value of 0.382, 0.382, 0.144, >0.95, and 0.254, respectively).

    Conclusion: This study indicates an association of IL-1B (-511C, -511T) polymorphism with CRSwNP and CRSsNP in our population, hence there is a possibility of IL-1B involvement in modulating pathogenesis of CRS. There was no significant association of IL-1A (+4845G, +4845T) polymorphism with CRSwNP and CRSsNP, and other factors related.

    Matched MeSH terms: Polymorphism, Restriction Fragment Length
  10. Ooi SX, Lee PL, Law HY, Say YH
    Asia Pac J Clin Nutr, 2010;19(4):491-8.
    PMID: 21147709
    Recently, the bitter receptor gene (TAS2R38) was identified to be responsible for phenylthiocarbamide (PTC) bitter sensitivity. Its two predominant haplotypes at three Single Nucleotide Polymorphisms (SNPs) are found to be definitive for the PTC status, which the ProAlaVal and AlaValIle haplotypes are associated with tasters and non-tasters, respectively. TAS2R38 haplotypes have been reported to influence food preferences (like cruciferous vegetables and fat foods) and cardiovascular disease risk factors. We examined, in 215 Malaysian subjects (100 males, 115 females), the association of the P49A SNP of TAS2R38 with anthropometric measurements and aversion to a list of 36 vegetables, 4 soy products, green tea and 37 sweet/fat foods. The subjects were successfully genotyped as 110 PA, 81 PP and 24 AA (with the A49 allelic frequency of 0.37), by Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP). Ethnicity (Malay, Chinese or Indian), but not gender, was associated with the P49A TAS2R38 genotypes (p<0.001). However, no significant differences in terms of Body Mass Index, Total Body Fat, waist circumference and Waist-Hip Ratio were found between the genotypes (p<0.05). Only aversions to green tea, mayonnaise and whipped cream, but not soy products, vegetables, and other sweet/fat foods, were associated with the P49A genotypes (p<0.05). Therefore, the P49A SNP of the bitter receptor gene TAS2R38 could not serve as a predictor of anthropometric measurements and aversion to vegetables or sweet/fat foods in the sampled Malaysian subjects, and this suggests the existence of other possible factors influencing food selection among Malaysians.
    Matched MeSH terms: Polymorphism, Restriction Fragment Length/genetics
  11. Azizah MR, Kuak SH, Ainol SS, Rahim MN, Normaznah Y, Norella K
    Asian Pac J Allergy Immunol, 2004;22(2-3):159-63.
    PMID: 15565953
    The etiology of systemic lupus erythematosus (SLE) is unknown but genetic factors seem to play a role in the disease pathogenesis. The tumor necrosis factor alpha (TNFa) gene, encoded at the TNF locus in the MHC class III region, is now known to be an important candidate gene in SLE, due to the proinflammatory activities of the TNFa. The objectives of this study were to examine the role of the TNFa polymorphism for the susceptibility of Malaysian Chinese lupus patients to SLE and to determine its association with organ involvement. The allelic frequencies of the TNFa polymorphic variant (TNF2) of seventy lupus patients were determined during follow-up at the Medical Clinic of the National University Hospital Malaysia by PCR-RFLP technique. Sixty-four females and 6 males with a mean age of 33+/-12 years were included. Clinical data were obtained from case records. Autoantibody levels were measured by ELISA. Fifty-nine ethnically-matched blood donors were used as controls. The allelic frequency of the TNF2 variant was found to be significantly increased in the patients compared to the controls (52.8% vs 33.8%). SLE patients with the polymorphic TNF2 variant were found to be at increased risk of central nervous system involvement (p = 0.004, RR = 2.59) and to have an increased frequency of anti-La antibodies (p = 0.03). In view of these findings we suggest that TNF2 variant is playing a role in conferring susceptibility to SLE and in the disease pathogenesis.
    Study site: Pusat Perubatan Universiti Kebangsaan Malaysia (PPUKM), Kuala Lumpur, Malaysia
    Matched MeSH terms: Polymorphism, Restriction Fragment Length
  12. Goh LP, Chong ET, Chua KH, Chuah JA, Lee PC
    Asian Pac J Cancer Prev, 2014;15(17):7377-81.
    PMID: 25227845
    CYP2E1 PstI polymorphism G-1259C (rs3813867) genotype distributions vary significantly among different populations and are associated with both diseases, like cancer, and adverse drug effects. To date, there have been limited genotype distributions and allele frequencies of this polymorphism reported in the three major indigenous ethnic groups (KadazanDusun, Bajau, and Rungus) in Sabah, also known as North Borneo. The aim of this study was to investigate the genotype distributions and allele frequencies of the CYP2E1 PstI polymorphism G-1259C in these three major indigenous peoples in Sabah. A total of 640 healthy individuals from the three dominant indigenous groups were recruited for this study. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) at G-1259C polymorphic site of CYP2E1 gene was performed using the Pst I restriction enzyme. Fragments were analyzed using agarose gel electrophoresis and confirmed by direct sequencing. Overall, the allele frequencies were 90.3% for c1 allele and 9.7% for c2 allele. The genotype frequencies for c1/c1, c1/c2 and c2/c2 were observed as 80.9%, 18.8%, and 0.3%, respectively. A highly statistical significant difference (p<0.001) was observed in the genotype distributions between indigenous groups in Sabah with all Asian and non-Asian populations. However, among these three indigenous groups, there was no statistical significant difference (p>0.001) in their genotype distributions. The three major indigenous ethnic groups in Sabah show unique genotype distributions when compared with other populations. This finding indicates the importance of establishing the genotype distributions of CYP2E1 PstI polymorphism in the indigenous populations.
    Matched MeSH terms: Polymorphism, Restriction Fragment Length
  13. Visuvanathan S, Chong PP, Yap YY, Lim CC, Tan MK, Lye MS
    Asian Pac J Cancer Prev, 2014;15(6):2747-51.
    PMID: 24761895
    BACKGROUND: DNA repair pathways play a crucial role in maintaining the human genome. Previous studies associated DNA repair gene polymorphisms (XPD Lys751Gln, XRCC1 Arg280His and XRCC1 Arg399Gln) with nasopharyngeal carcinoma. These non-synonymous polymorphisms may alter DNA repair capacity and thus increase or decrease susceptibility. The present study aimed to determine the genotype distribution of XPD codon 751, XRCC1 codon 280 and codon 399 polymorphisms and haplotype associations among NPC cases and controls in the Malaysian population.

    MATERIALS AND METHODS: We selected 157 NPC cases and 136 controls from two hospitals in Kuala Lumpur, Malaysia for this study. The polymorphisms studied were genotyped by PCR-RFLP assay and allele and genotype frequencies, haplotype and linkage disequilibrium were determined using SNPstat software.

    RESULTS: For the XPD Lys751Gln polymorphism, the frequency of the Lys allele was higher in cases than in controls (94.5% versus 85.0%). For the XRCC1 Arg280His polymorphism, the frequency of Arg allele was 90.0% and 89.0% in cases and controls, respectively and for XRCC1 Arg399Gln the frequency of the Arg allele was 72.0% and 72.8% in cases and controls respectively. All three polymorphisms were in linkage disequilibrium. The odds ratio from haplotype analysis for these three polymorphisms and their association with NPC was 1.93 (95%CI: 0.90-4.16) for haplotype CGC vs AGC allele combinations. The global haplotype association with NPC gave a p-value of 0.054.

    CONCLUSIONS: Our study provides an estimate of allele and genotype frequencies of XRCC1Arg280His, XRCC1 Arg399Gln and XPD Lys751Gln polymorphisms in the Malaysian population and showed no association with nasopharyngeal cancer.

    Matched MeSH terms: Polymorphism, Restriction Fragment Length
  14. Halim NH, Chong ET, Goh LP, Chuah JA, See EU, Chua KH, et al.
    Asian Pac J Cancer Prev, 2016;17(4):1925-31.
    PMID: 27221877
    BACKGROUND: The XRCC1 protein facilitates various DNA repair pathways; single-nucleotide polymorphisms (SNPs) in this gene are associated with a risk of gastrointestinal cancer (GIC) with inconsistent results, but no data have been previously reported for the Sabah, North Borneo, population. We accordingly investigated the XRCC1 Arg194Trp and Arg399Gln SNPs in terms of GIC risk in Sabah.

    MATERIALS AND METHODS: We performed genotyping for both SNPs for 250 GIC patients and 572 healthy volunteers using a polymerase chain reaction- restriction fragment length polymorphism approach. We validated heterozygosity and homozygosity for both SNPs using direct sequencing.

    RESULTS: The presence of a variant 194Trp allele in the Arg194Trp SNP was significantly associated with a higher risk of GIC, especially with gastric and colorectal cancers. We additionally found that the variant 399Gln allele in Arg399Gln SNP was associated with a greater risk of developing gastric cancer. Our combined analysis revealed that inheritance of variant alleles in both SNPs increased the GIC risk in Sabah population. Based on our etiological analysis, we found that subjects ≥50 years and males who carrying the variant 194Trp allele, and Bajau subjects carrying the 399Gln allele had a significantly increased risk of GIC.

    CONCLUSIONS: Our findings suggest that inheritance of variant alleles in XRCC1 Arg194Trp and Arg399Gln SNPs may act as biomarkers for the early detection of GIC, especially for gastric and colorectal cancers in the Sabah population.

    Matched MeSH terms: Polymorphism, Restriction Fragment Length
  15. Chong ET, Goh LP, See EU, Chuah JA, Chua KH, Lee PC
    Asian Pac J Cancer Prev, 2016;17(2):647-53.
    PMID: 26925658
    BACKGROUND: Breast cancer is the most common type of cancer affecting Malaysian women. Recent statistics revealed that the cumulative probability of breast cancer and related deaths in Malaysia is higher than in most of the countries of Southeast Asia. Single nucleotide polymorphisms (SNPs) in CYP2E1 (rs6413432 and rs3813867), STK15 (rs2273535 and rs1047972) and XRCC1 (rs1799782 and rs25487) have been associated with breast cancer risk in a meta-analysis but any link in Southeast Asia, including Malaysia, remained to be determined. Hence, we investigated the relationship between these SNPs and breast cancer risk among Malaysian women in the present case-control study.

    MATERIALS AND METHODS: Genomic DNA was isolated from peripheral blood of 71 breast cancer patients and 260 healthy controls and subjected to polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis.

    RESULTS: Our study showed that the c1/c2 genotype or subjects with at least one c2 allele in CYP2E1 rs3813867 SNP had significantly increased almost 1.8-fold higher breast cancer risk in Malaysian women overall. In addition, the variant Phe allele in STK15 rs2273535 SNP appeared to protect against breast cancer in Malaysian Chinese. No significance association was found between XRCC1 SNPs and breast cancer risk in the population.

    CONCLUSIONS: This study provides additional knowledge on CYP2E1, STK15 and XRCC1 SNP impact of risk of breast cancer, particularly in the Malaysian population. From our findings, we also recommend Malaysian women to perform breast cancer screening before 50 years of age.

    Matched MeSH terms: Polymorphism, Restriction Fragment Length
  16. Tan YH, Sidik SM, Syed Husain SN, Lye MS, Chong PP
    Asian Pac J Cancer Prev, 2016;17(1):57-64.
    PMID: 26838255
    BACKGROUND: Tobacco smoking is considered a risk factor for cervical cancer development due to the presence of tobacco based carcinogenic metabolites in cervical cells of female smokers. In this study, we investigated the role of the T3801C (MspI) polymorphism of CYP1A1, a gene encoding an enzyme necessary for the initiation of tobacco based carcinogen metabolism, on cervical cancer risk. The T to C substitution may alter CYP1A1 activities, potentially elevating cervical cancer risk. Since results of gene-disease association studies vary according to the study population, the multi-ethnic population of Malaysia provides an excellent representative cohort for identifying and comparing the cervical cancer risk among the 3 major ethnics in Southeast Asia in relation to CYP1A1 MspI polymorphism.

    MATERIALS AND METHODS: A total of 195 Thin Prep Pap smear samples from HPV negative and cancer free females were randomly selected as controls while 106 formalin fixed paraffin embedded samples from females with invasive cervical cancer were randomly selected for the cases group. The polymorphisms were identified using restriction fragment length polymorphism (RFLP) PCR.

    RESULTS: We found no significant associations between CYP1A1 MspI polymorphism and cervical cancer in the general Malaysian female population. However, upon ethnic stratification, the variant C/C genotype was significantly associated with a 4.66-fold increase in cervical cancer risk in Malay females (95% CI= 1.21-17.9; p=0.03). No significant association was observed in the Chinese and Indian females. Additionally, there were no significant associations in the dominant model and allele frequency model analysis in both the general and ethnically stratified female population of Malaysia.

    CONCLUSIONS: Our findings suggest that the C/C genotype of CYP1A1 MspI polymorphism is associated with the development of cervical carcinoma in the Malay females of Malaysia.

    Matched MeSH terms: Polymorphism, Restriction Fragment Length/genetics*
  17. Mohamed Yusoff AA, Zulfakhar FN, Sul’ain MD, Idris Z, Abdullah JM
    Asian Pac J Cancer Prev, 2016 12 01;17(12):5195-5201.
    PMID: 28125199
    Background: Brain tumors, constituting one of the most deadly forms of cancer worldwide, result from the accumulation of multiple genetic and epigenetic alterations in genes and signaling pathways. Isocitrate dehydrogenase enzyme isoform 1 (IDH1) mutations are frequently identified in primary brain tumors and acute myeloid leukemia. Studies on IDH1 gene mutations have been extensively performed in various populations worldwide but not in Malaysia. This work was conducted to study the prevalence of IDH1 c.395G>A (R132H) hotspot mutations in a group of Malaysian patients with brain tumors in order to gain local data for the IDH1 mutation profile in our population. Methods: Mutation analysis of c.395G>A (R132H) of IDH1 was performed in 40 brain tumor specimens by the polymerase chain reaction-restriction fragment length polymorphism method (PCR-RFLP) and then verified by direct sequencing. Associations between the IDH1 c.395G>A (R132H) mutation and clinicopathologic characteristics were also analyzed. Results: The IDH1 c.395G>A (R132H) mutation was detected in 14/40 patients (35%). A significant association was found with histological tumor types, but not with age, gender and race. Conclusions: IDH1 is frequently mutated and associated with histological subtypes in Malay brain tumors.
    Matched MeSH terms: Polymorphism, Restriction Fragment Length
  18. Sainei NE, Kumar VS, Chin YS, Salih FAM
    Asian Pac J Cancer Prev, 2018 Oct 26;19(10):2807-2813.
    PMID: 30360610
    Background: Cervical cancer is currently the third most common female cancer in Malaysia , with the human
    papillomavirus (HPV) considered as one of the important contributory factors. This study was conducted to determine
    HPV prevalence, its genotype distribution, and other potential risk factors among women in Kota Kinabalu, Sabah
    in order to evaluate the likely efficacy of current HPV vaccines in the local population. Methods: A total of 240
    cervical samples were collected and subjected to DNA extraction, PCR amplification using the MY09/MY11 primer
    pair, and restriction fragment length polymorphism (RFLP) for HPV detection and genotyping. Sociodemographic,
    clinical, and behavioural data were also collected via questionnaires. Results: The prevalence of HPV infection was
    9.6%. The most common HPVs among 13 genotypes were high-risk HPV-56 (16.7%) and probable high-risk HPV-70
    (16.7%) followed by HPV-16, -58, -53, -61, -33, -59, and -66 (in decreasing order of prevalence) including the rare
    genotypes: HPV-62, -81, -82 and -84. Statistical analyses using logistic regression models showed that HPV infection
    was significantly associated with employment (OR 4.94; CI 1.58-15.40) and education at secondary/high school level
    (OR 0.13; CI 0.03-0.62). Conclusion: Distribution of HPV genotypes in Sabah indicated a high prevalence of HPV-56
    and -70 which are among the rare HPV types in West Malaysia and merit consideration in future strategies for HPV
    vaccination specifically for local Sabahan women.
    Matched MeSH terms: Polymorphism, Restriction Fragment Length/genetics
  19. Hao Ing Y, Md Salleh MS, Yahya MM, Ankathil R, Abdul Aziz AA
    Asian Pac J Cancer Prev, 2023 Nov 01;24(11):3891-3897.
    PMID: 38019248 DOI: 10.31557/APJCP.2023.24.11.3891
    OBJECTIVE: The aim of this study was to elucidate the association of ATP-binding cassette super-family G member 2 (ABCG2) gene polymorphisms with individual susceptibility to Triple Negative Breast Cancer (TNBC) as well as clinicopathological variables in TNBC patients. Two common polymorphisms in Asian population, ABCG2 34 G>A and 421 C>A was selected in this study.

    METHODS: Blood samples were collected from 75 TNBC patients and 83 controls. Genomic DNA was extracted from blood samples and the SNP genotyping was performed by using PCR-RFLP technique. The genotypes were characterized and grouped into homozygous wildtype, heterozygote and homozygous variant based on the band size. The result was subjected to statistical analysis.

    RESULTS: The A allele and AA genotype of ABCG2 421 C>A had OR of 3.011 (p=0.003, 95% CI: 1.417-6.398) and 9.042 (p=0.011, 95% CI: 1.640-49.837), to develop advanced staging carcinoma respectively. The AA genotype of ABCG2 421 C>A polymorphism was also associated with metaplastic and medullary carcinoma with an OR of 6.429 (p=0.018, 95% CI: 1.373-30.109). A significant association was also found in haplotype 34G/421A of ABCG2 with advanced cancer staging as well as metaplastic and medullary carcinoma with OR of 2.347 (p=0.032, 95% CI: 1.010-5.560) and 2.546 (p=0.008, 95% CI: 1.005-6.447), respectively.  Conclusion: The present study suggests that ABCG2 421 C>A polymorphism was associated with metaplastic and medullary histology and advanced cancer staging in TNBC patients.

    Matched MeSH terms: Polymorphism, Restriction Fragment Length
  20. Puvanesuaran VR, Noordin R, Balakrishnan V
    Avian Dis, 2013 Mar;57(1):128-32.
    PMID: 23678741
    Toxoplasma gondii is a parasitic protozoan that infects nearly one-third of humans. The present study was performed to isolate and genotype T. gondii from free-range ducks in Malaysia. Sera, heads, and hearts from 205 ducks were obtained from four states in Peninsular Malaysia, and 30 (14.63%) sera were found to be seropositive when assayed with the modified agglutination test (MAT > or = 1:6). All the positive samples were inoculated into mice, and T. gondii was successfully isolated from four individual duck samples (1.95%), which were initially found to be strongly seropositive (MAT > or = 1:24). The isolates were subjected to PCR-RFLP analysis, and two T. gondii strains were identified: type I and type II. This is the first reported study on the genetic characterization of T. gondii isolates from free-range farm animals in Southeast Asia.
    Matched MeSH terms: Polymorphism, Restriction Fragment Length
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