Displaying publications 21 - 40 of 1095 in total

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  1. A molecular epidemiological study targeting the glycoprotein gene of rabies virus isolates from China
    Meng SL, Yan JX, Xu GL, Nadin-Davis SA, Ming PG, Liu SY, et al.
    Virus Res, 2007 Mar;124(1-2):125-38.
    PMID: 17129631
    A group of 31 rabies viruses (RABVs), recovered primarily from dogs, one deer and one human case, were collected from various areas in China between 1989 and 2006. Complete G gene sequences determined for these isolates indicated identities of nucleotide and amino acid sequences of >or=87% and 93.8%, respectively. Phylogenetic analysis of these and some additional Chinese isolates clearly supported the placement of all Chinese viruses in Lyssavirus genotype 1 and divided all Chinese isolates between four distinct groups (I-IV). Several variants identified within the most commonly encountered group I were distributed according to their geographical origins. A comparison of representative Chinese viruses with other isolates retrieved world-wide indicated a close evolutionary relationship between China group I and II viruses and those of Indonesia while China group III viruses formed an outlying branch to variants from Malaysia and Thailand. China group IV viruses were closely related to several vaccine strains. The predicted glycoprotein sequences of these RABVs variants are presented and discussed with respect to the utility of the anti-rabies biologicals currently employed in China.
    Matched MeSH terms: Genotype
  2. Fulltext A multi-ethnic study of a PNPLA3 gene variant and its association with disease severity in non-alcoholic fatty liver disease
    Zain SM, Mohamed R, Mahadeva S, Cheah PL, Rampal S, Basu RC, et al.
    Hum Genet, 2012 Jul;131(7):1145-52.
    PMID: 22258181 DOI: 10.1007/s00439-012-1141-y
    The adiponutrin (PNPLA3) rs738409 polymorphism has been found to be associated with susceptibility to non-alcoholic fatty liver disease (NAFLD) in various cohorts. We further investigated the association of this polymorphism with non-alcoholic steatohepatitis (NASH) severity and with histological features of NAFLD. A total of 144 biopsy-proven NAFLD patients and 198 controls were genotyped for PNPLA3 gene polymorphism (rs738409 C>G). The biopsy specimens were histologically graded by a qualified pathologist. We observed an association of G allele with susceptibility to NAFLD in the pooled subjects (OR 2.34, 95% CI 1.69-3.24, p < 0.0001), and following stratification, in each of the three ethnic subgroups, namely Chinese, Indian and Malay (OR 1.94, 95% CI 1.12-3.37, p = 0.018; OR 3.51, 95% CI 1.69-7.26, p = 0.001 and OR 2.05, 95% CI 1.25-3.35, p = 0.005, respectively). The G allele is associated with susceptibility to NASH (OR 2.64, 95% CI 1.85-3.75, p < 0.0001), with NASH severity (OR 1.85, 95% CI 1.05-3.26, p = 0.035) and with presence of fibrosis (OR 1.95, 95% CI 1.17-3.26, p = 0.013) but not with simple steatosis nor with other histological parameters. Although the serum triglyceride level is significantly higher in NAFLD patients compared to controls, the G allele is associated with decreased level of triglycerides (p = 0.029) in the NAFLD patients. Overall, the rs738409 G allele is associated with severity of NASH and occurrence of fibrosis in patients with NAFLD.
    Matched MeSH terms: Genotype
  3. Fulltext A newly emerging HIV-1 recombinant lineage (CRF58_01B) disseminating among people who inject drugs in Malaysia
    Chow WZ, Takebe Y, Syafina NE, Prakasa MS, Chan KG, Al-Darraji HA, et al.
    PLoS One, 2014;9(1):e85250.
    PMID: 24465513 DOI: 10.1371/journal.pone.0085250
    The HIV epidemic is primarily characterised by the circulation of HIV-1 group M (main) comprising of 11 subtypes and sub-subtypes (A1, A2, B-D, F1, F2, G, H, J, and K) and to date 55 circulating recombinant forms (CRFs). In Southeast Asia, active inter-subtype recombination involving three main circulating genotypes--subtype B (including subtype B', the Thai variant of subtype B), CRF01_AE, and CRF33_01B--have contributed to the emergence of novel unique recombinant forms. In the present study, we conducted the molecular epidemiological surveillance of HIV-1 gag-RT genes among 258 people who inject drugs (PWIDs) in Kuala Lumpur, Malaysia, between 2009 and 2011 whereby a novel CRF candidate was recently identified. The near full-length genome sequences obtained from six epidemiologically unlinked individuals showed identical mosaic structures consisting of subtype B' and CRF01_AE, with six unique recombination breakpoints in the gag-RT, pol, and env regions. Among the high-risk population of PWIDs in Malaysia, which was predominantly infected by CRF33_01B (>70%), CRF58_01B circulated at a low but significant prevalence (2.3%, 6/258). Interestingly, the CRF58_01B shared two unique recombination breakpoints with other established CRFs in the region: CRF33_01B, CRF48_01B, and CRF53_01B in the gag gene, and CRF15_01B (from Thailand) in the env gene. Extended Bayesian Markov chain Monte Carlo sampling analysis showed that CRF58_01B and other recently discovered CRFs were most likely to have originated in Malaysia, and that the recent spread of recombinant lineages in the country had little influence from neighbouring countries. The isolation, genetic characterization, and evolutionary features of CRF58_01B among PWIDs in Malaysia signify the increasingly complex HIV-1 diversity in Southeast Asia that may hold an implication on disease treatment, control, and prevention.
    Matched MeSH terms: Genotype
  4. A novel HLA-B*27 allele, B*27:138, identified by sequence-based typing
    Koay BT, Norfarhana KF, Norhafizi MY, Lee YY, Dhaliwal JS
    Tissue Antigens, 2015 Aug;86(2):143-4.
    PMID: 26105122 DOI: 10.1111/tan.12599
    Ankylosing spondylitis (AS) is a chronic inflammatory disorder with predilection for the axial skeleton, leading to progressive restricted mobility and deformity of the spine. The fundamental mechanism involves autoimmunity orchestrated by T cells. Similar to other rheumatic diseases, the complex interplay of cytokines such as tumour necrosis factor alpha, interleukin-6 (IL 6) and interleukin-10 (IL 10) has been implicated in the pathogenesis of the disease. Despite extensive research over the past decades, the treatment options for AS, are limited. Non steroidal antiinflammatory drugs are the first line of therapy, whereas anti TNF drugs are administered for refractory cases which fail to respond to the treatment. There have been conflicting views on the correlation of IL 6 with disease activity in AS. As such, the debate on the role of anti IL6 in AS is still ongoing. Anti IL 6 such as tocilizumab and siltuximab have proven efficacy based on the large randomized controlled trials. The Food and Drug Administration (FDA) has approved these drugs for treating rheumatoid arthritis and systemic juvenile idiopathic arthritis. Researchers have adventurously experimented anti IL 6 therapy in AS but the conclusions made were not consolidated into international guidelines or consensus statement for clinical practice. In the present review, we explore the role of anti IL6 in the treatment of AS based on the cumulative evidence over recent years.
    Matched MeSH terms: Genotype
  5. A novel ITPA variant causes epileptic encephalopathy with multiple-organ dysfunction
    Sakamoto M, Kouhei D, Haniffa M, Silva S, Troncoso M, Santander P, et al.
    J Hum Genet, 2020 Sep;65(9):751-757.
    PMID: 32405030 DOI: 10.1038/s10038-020-0765-3
    Inborn errors of metabolism can cause epileptic encephalopathies. Biallelic loss-of-function variants in the ITPA gene, encoding inosine triphosphate pyrophosphatase (ITPase), have been reported in epileptic encephalopathies with lack of myelination of the posterior limb of the internal capsule, brainstem tracts, and tracts to the primary visual and motor cortices (MIM:616647). ITPase plays an important role in purine metabolism. In this study, we identified two novel homozygous ITPA variants, c.264-1 G > A and c.489-1 G > A, in two unrelated consanguineous families. The probands had epilepsy, microcephaly with characteristic magnetic resonance imaging findings (T2 hyperintensity signals in the pyramidal tracts of the internal capsule, delayed myelination, and thin corpus callosum), hypotonia, and developmental delay; both died in early infancy. Our report expands the knowledge of clinical consequences of biallelic ITPA variants.
    Matched MeSH terms: Genotype
  6. Fulltext A novel rare copy number variant of the ABCF1 gene identified among dengue fever patients from Peninsular Malaysia
    Hoh BP, Sam SS, Umi SH, Mahiran M, Nik Khairudin NY, Rafidah Hanim S, et al.
    Genet. Mol. Res., 2014;13(1):980-5.
    PMID: 24634119 DOI: 10.4238/2014.February.19.9
    Copy number variation (CNV) is a form of genetic variation in addition to single nucleotide polymorphisms. The significance of CNV in the manifestation of a number of diseases is only recently receiving considerable attention. We genotyped 163 dengue patients from Peninsular Malaysia for genes possibly linked to dengue infection using quantitative real-time PCR. Here, we report a serendipitous discovery of a novel rare CNV of the ABCF1 gene among the dengue patients. Among these patients, two had a gain of 1 copy (CN = 3) and one had lost 1 copy (CN = 1), indicating that a rare CNV of the ABCF1 gene was detected among dengue patients from Peninsular Malaysia. Although the gene is suspected to regulate inflammatory responses and pathogen-induced cytokine storm, its relevance to dengue requires further investigation.
    Matched MeSH terms: Genotype
  7. Fulltext A persistent antimicrobial resistance pattern and limited methicillin-resistance-associated genotype in a short-term Staphylococcus aureus carriage isolated from a student population
    Mat Azis N, Pung HP, Abdul Rachman AR, Amin Nordin S, Sarchio SNE, Suhaili Z, et al.
    J Infect Public Health, 2017 Mar-Apr;10(2):156-164.
    PMID: 27033676 DOI: 10.1016/j.jiph.2016.02.013
    The aim of the present study was to assess and compare the antimicrobial susceptibility pattern against a panel of antibiotics and molecular and methicillin resistance-associated genotypes of 120 carriage S. aureus isolates previously isolated from a student population at two isolation events within a one-month interval. The antibiotic susceptibility of isolates was determined using the Kirby-Bauer disc-diffusion method (cefoxitin by Etest). The MRSA was screened using polymerase chain reaction for the presence of the mecA gene. The mecA-positive isolates were subjected to staphylococcal cassette chromosome (SCC) mec typing, multilocus sequence typing (MLST) and eBURST analysis. All isolates were characterized for the presence of the Panton-Valentine leukocidin (PVL) gene, an enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR) pattern and the spa type. For the two occasions where S. aureus was isolated, the highest frequency of resistance was observed for penicillin (70% and 65%, respectively), with a lower rate against erythromycin and tetracycline (<12%). All isolates were susceptible to ciprofloxacin and gentamycin. As for methicillin resistance, eight isolates had minimum inhibitory concentrations (MIC) of resistant categories, but 10 isolates (8.33%) were positive for the mecA gene. The mecA-positive isolates belonged to SCCmec types I (n=9) and V (n=1). MLST was resolved for only three MRSAs, ST508 (n=1), ST88 (n=1) and ST96 (n=1). The results of the eBURST analysis showed that the MRSA isolates analyzed in the present study were potentially related to MRSA identified in other countries. Approximately half of the persistent S. aureus carriers harbored S. aureus of a similar spa type in the respective individuals during both isolation events. A persistent antimicrobial pattern and limited distinct MRSAs were observed over the short study period. The latter frequently exhibited SCCmec type I, commonly associated with hospital-acquired (HA) characteristics, but further delineation is needed to justify the origins of these bacteria.
    Matched MeSH terms: Genotype*
  8. Fulltext A pilot study on cytotoxic T lymphocyte-4 gene polymorphisms in urinary schistosomiasis
    Idris ZM, Yazdanbakhsh M, Adegnika AA, Lell B, Issifou S, Noordin R
    Genet Test Mol Biomarkers, 2012 Jun;16(6):488-92.
    PMID: 22288822 DOI: 10.1089/gtmb.2011.0209
    Urinary schistosomiasis is caused by the digenetic trematode Schistosoma haematobium, characterized by accumulation of eggs in the genitourinary tract. Cytotoxic T-lymphocyte antigen 4 (CTLA-4) can play an important role in parasitic infection due to its major role as a negative regulator of T-cell activation and proliferation. This study was performed in patients with schistosomiasis and healthy controls to analyze the allele and genotype frequencies of four CTLA-4 gene polymorphisms. The CTLA-4 gene was amplified using Taqman real-time polymerase chain reaction, and allele and genotypes of 49 patients with schistosomiasis were analyzed using allelic discrimination analysis followed by subsequent direct sequencing. The results were compared with healthy control subjects. The frequencies of CTLA-4 rs733618 A allele at position -1722 (p=0.001), rs11571316 C allele at position -1577 (p<0.001), and rs231775 A allele at position +49 (p=0.002) in the patient group were significantly higher than the control group. The rs733618 AA genotype (p=0.001), rs11571316 CC genotype (p<0.001), and rs231775 AA genotype (p=0.007) were also significantly overrepresented. Meanwhile, rs733618 AG genotype (p=0.001), rs11571316 CT genotype (p=0.02), and rs231775 GG genotype (p=0.029) were significantly decreased in the patients with schistosomiasis, as compared with the controls. No significant difference was observed in both allele and genotype of rs16841252. The results of this study suggest that the rs733618, rs11571316, and rs231775 polymorphisms in the CTLA-4 gene may influence susceptibility to schistosomiasis infection in the Gabonese children.
    Matched MeSH terms: Genotype
  9. Fulltext A potential epigenetic marker mediating serum folate and vitamin B12 levels contributes to the risk of ischemic stroke
    Wei LK, Sutherland H, Au A, Camilleri E, Haupt LM, Gan SH, et al.
    Biomed Res Int, 2015;2015:167976.
    PMID: 25705649 DOI: 10.1155/2015/167976
    Stroke is a multifactorial disease that may be associated with aberrant DNA methylation profiles. We investigated epigenetic dysregulation for the methylenetetrahydrofolate reductase (MTHFR) gene among ischemic stroke patients. Cases and controls were recruited after obtaining signed written informed consents following a screening process against the inclusion/exclusion criteria. Serum vitamin profiles (folate, vitamin B12, and homocysteine) were determined using immunoassays. Methylation profiles for CpGs A and B in the MTHFR gene were determined using a bisulfite-pyrosequencing method. Methylation of MTHFR significantly increased the susceptibility risk for ischemic stroke. In particular, CpG A outperformed CpG B in mediating serum folate and vitamin B12 levels to increase ischemic stroke susceptibility risks by 4.73-fold. However, both CpGs A and B were not associated with serum homocysteine levels or ischemic stroke severity. CpG A is a potential epigenetic marker in mediating serum folate and vitamin B12 to contribute to ischemic stroke.
    Matched MeSH terms: Genotype
  10. Fulltext A rare FANCA gene variation as a breast cancer susceptibility allele in an Iranian population
    Abbasi S, Rasouli M
    Mol Med Rep, 2017 Jun;15(6):3983-3988.
    PMID: 28440412 DOI: 10.3892/mmr.2017.6489
    Fanconi Anemia (FA) is an autosomal recessive syndrome characterized by congenital abnormalities, progressive bone marrow failure and Fanconi anemia complementation group A (FANCA) is also a potential breast and ovarian cancer susceptibility gene. A novel allele with tandem duplication of 13 base pair sequence in promoter region was identified. To investigate whether the 13 base pair sequence of tandem duplication in promoter region of the FANCA gene is of high penetrance in patients with breast cancer and to determine if the presence of the duplicated allele was associated with an altered risk of breast cancer, the present study screened DNA in blood samples from 304 breast cancer patients and 295 normal individuals as controls. The duplication allele had a frequency of 35.4 and 21.2% in patients with breast cancer and normal controls, respectively. There was a significant increase in the frequency of the duplication allele in patients with familial breast cancer compared with controls (45.1%, P=0.001). Furthermore, the estimated risk of breast cancer in individuals with a homozygote [odds ratio (OR), 4.093; 95% confidence intervals (CI), 1.957‑8.561] or heterozygote duplicated genotype (OR, 3.315; 95% CI, 1.996‑5.506) was higher compared with the corresponding normal homozygote genotype. In conclusion, the present study indicated that the higher the frequency of the duplicated allele, the higher the risk of breast cancer. To the best of our knowledge, the present study is the first to report FANCA gene duplication in patients with breast cancer.
    Matched MeSH terms: Genotype
  11. Fulltext A replication study confirms the association of dendritic cell immunoreceptor (DCIR) polymorphisms with ACPA - negative RA in a large Asian cohort
    Guo J, Wu X, Too CL, Yin F, Lu X, He J, et al.
    PLoS One, 2012;7(7):e41228.
    PMID: 22829930 DOI: 10.1371/journal.pone.0041228
    OBJECTIVES: Dendritic cell immunoreceptor (DCIR) has been implicated in development of autoimmune disorders in rodent and DCIR polymorphisms were associated with anti-citrullinated proteins antibodies (ACPA)-negative rheumatoid arthritis (RA) in Swedish Caucasians. This study was undertaken to further investigate whether DCIR polymorphisms are also risk factors for the development of RA in four Asian populations originated from China and Malaysia.

    METHODS: We genotyped two DCIR SNPs rs2377422 and rs10840759 in Han Chinese population (1,193 cases, 1,278 controls), to assess their association with RA. Subsequently, rs2377422 was further genotyped in three independent cohorts of Malaysian-Chinese subjects (MY_Chinese, 254 cases, 206 controls), Malay subjects (MY_ Malay, 515 cases, 986 controls), and Malaysian-Indian subjects (MY_Indian, 378 cases, 285 controls), to seek confirmation of association in various ethnic groups. Meta-analysis was preformed to evaluate the contribution of rs2377422 polymorphisms to the development of ACPA-negative RA in distinct ethnic groups. Finally, we carried out association analysis of rs2377422 polymorphisms with DCIR mRNA expression levels.

    RESULTS: DCIR rs2377422 was found to be significantly associated with ACPA -negative RA in Han Chinese (OR 1.92, 95% CI 1.27-2.90, P=0.0020). Meta-analysis confirms DCIR rs2377422 as a risk factor for ACPA-negative RA across distinct ethnic groups (OR(overall) =1.17, 95% CI 1.06-1.30, P=0.003). The SNP rs2377422 polymorphism showed significant association with DCIR mRNA expression level, i.e. RA-risk CC genotype exhibit a significant increase in the expression of DCIR (P=0.0023, Kruskal-Wallis).

    CONCLUSIONS: Our data provide evidence for association between DCIR rs2377422 and RA in non-Caucasian populations and confirm the influence of DCIR polymorphisms on RA susceptibility, especially on ACPA-negative RA.
    Matched MeSH terms: Genotype
  12. A simple PCR method for rapid genotype analysis of Mycobacterium ulcerans
    Stinear T, Davies JK, Jenkin GA, Portaels F, Ross BC, Oppedisano F, et al.
    J Clin Microbiol, 2000 Apr;38(4):1482-7.
    PMID: 10747130
    Two high-copy-number insertion sequences, IS2404 and IS2606, were recently identified in Mycobacterium ulcerans and were shown by Southern hybridization to possess restriction fragment length polymorphism between strains from different geographic origins. We have designed a simple genotyping method that captures these differences by PCR amplification of the region between adjacent copies of IS2404 and IS2606. We have called this system 2426 PCR. The method is rapid, reproducible, sensitive, and specific for M. ulcerans, and it has confirmed previous studies suggesting a clonal population structure of M. ulcerans within a geographic region. M. ulcerans isolates from Australia, Papua New Guinea, Malaysia, Surinam, Mexico, Japan, China, and several countries in Africa were easily differentiated based on an array of 4 to 14 PCR products ranging in size from 200 to 900 bp. Numerical analysis of the banding patterns suggested a close evolutionary link between M. ulcerans isolates from Africa and southeast Asia. The application of 2426 PCR to total DNA, extracted directly from M. ulcerans-infected tissue specimens without culture, demonstrated the sensitivity and specificity of this method and confirmed for the first time that both animal and human isolates from areas of endemicity in southeast Australia have the same genotype.
    Matched MeSH terms: Genotype
  13. A simple and rapid genotyping method for beta-2 receptor (beta2 AR) gene using allele specific multiplex PCR
    Romaino SM, Teh LK, Zilfalil BA, Thong CP, Ismail AA, Amir J, et al.
    J Clin Pharm Ther, 2004 Feb;29(1):47-52.
    PMID: 14748897 DOI: 10.1046/j.1365-2710.2003.00535.x
    Polymorphism of the beta2-adrenergic receptor (beta2 AR) gene is an important determinant of the function of this receptor. It affects receptor down-regulation and beta2-agonist responses. It has also been a focus of interest in attempts to elucidate the genetic basis of asthma, hypertension, obesity and cystic fibrosis. Several different techniques have been established to determine beta2 AR genotypes but none of these methods are simple enough to detect simultaneously all the five alleles of our research interest (Arg16/Gly16, -20T/C, Gln27/Glu27, -47T/C and Thr164/Ile164).
    Matched MeSH terms: Genotype
  14. A simple method for the detection of CYP2C9 polymorphisms: nested allele-specific multiplex polymerase chain reaction
    Zainuddin Z, Teh LK, Suhaimi AW, Salleh MZ, Ismail R
    Clin Chim Acta, 2003 Oct;336(1-2):97-102.
    PMID: 14500040 DOI: 10.1016/s0009-8981(03)00319-x
    BACKGROUND: Cytochrome P4502C9 (CYP2C9), a principle drug-metabolizing enzyme is polymorphic in humans and is responsible for important pharmacokinetic and pharmacodynamic variations of CYP2C9 substrates. We developed an allele-specific multiplex polymerase chain reaction (PCR) method for the detection of common CYP2C9 alleles.
    METHOD: Genomic DNA was extracted from blood obtained from 40 unrelated healthy Malaysian Indian volunteers. The DNA was subjected to a first PCR that was used to amplify both exons 3 and 7 simultaneously in one reaction tube and a second PCR that was used to detect the polymorphic sites of CYP2C9 alleles using allele-specific primers. Sequencing was performed to validate the test results.
    RESULTS: We were successful in amplifying the fragments of interest from the DNA samples. The method was also reproducible and specific. The amplified sequences showed 100% homology to CYP2C9 sequence.
    CONCLUSION: This is the first nested allele-specific multiplex PCR method reported to allow for the simultaneously detection of five CYP2C9 alleles.
    Matched MeSH terms: Genotype
  15. A simple multiplex PCR method for the concurrent detection of three CYP2C8 variants
    Muthiah YD, Lee WL, Teh LK, Ong CE, Salleh MZ, Ismail R
    Clin Chim Acta, 2004 Nov;349(1-2):191-8.
    PMID: 15469873 DOI: 10.1016/j.cccn.2004.06.024
    BACKGROUND: Cytochrome P450 (CYP) 2C8 is a principle enzyme responsible for the metabolism of many clinically important drugs as well as endogenous compounds such as arachidonic acid. The enzyme is genetically polymorphic but a simple method is not available to study its genetic polymorphism. We developed and optimized a variant-specific PCR techniques to detect CYP2C8*2, CYP2C8*3 and CYP2C8*4.
    METHOD: Genomic DNA was extracted from blood using standard extraction methods. A two-step PCR method was developed to detect simultaneously three CYP2C8 variants. In the first PCR (PCR1), specific regions from exons 3, 5 and 8 of the CYP2C8 gene were amplified. The products were used as templates in parallel alleles-specific PCR (PCR2). This method was tested against DNA samples obtained from 57 healthy Malaysian volunteers.
    RESULT: The bands of interest were successfully amplified. This method showed specific and reproducible results when tested on healthy volunteers. DNA sequencing further confirmed genotype results obtained from current method.
    CONCLUSION: We have successfully developed and optimized a multiplex PCR method suitable for use in population studies of CYP2C8 polymorphism.
    Matched MeSH terms: Genotype
  16. A study on the genetic polymorphisms of CYP3A5 among the Orang Asli in Malaysia using a next generation sequencing platform
    Ang GY, Yu CY, Johari James R, Ahmad A, Abdul Rahman T, Mohd Nor F, et al.
    Ann Hum Biol, 2018 Mar;45(2):166-169.
    PMID: 29447003 DOI: 10.1080/03014460.2018.1440004
    BACKGROUND: CYP3A5 is the predominant sub-family of biotransformation enzymes in the liver and the genetic variations in CYP3A5 are an important determinant of inter-individual and inter-ethnic differences in CYP3A-mediated drug disposition and response.

    AIM: This study aims to investigate the genetic polymorphisms of CYP3A5 among the Orang Asli in Peninsular Malaysia using a next generation sequencing platform.

    METHODS: Genomic DNAs were extracted from blood samples of the three main Orang Asli tribes and whole-genome sequencing was performed.

    RESULTS: A total of 61 single nucleotide polymorphisms were identified and all the SNPs were located in introns except rs15524, which is in the 3'UTR, and 11 of these polymorphisms were novel. Two allelic variants and three genotypes were identified in the Orang Asli. The major allelic variant was the non-functional CYP3A5*3 (66.4%). The percentages of Orang Asli with CYP3A5*3/*3 (47.2%) and CYP3A5*1/*3 (38.1%) genotypes are more than twice the percentage of Orang Asli with CYP3A5*1/*1 (14.8%) genotype. Almost half of the Orang Asli harboured CYP3A5 non-expressor genotype (CYP3A5*3/*3).

    CONCLUSIONS: The predominance of the CYP3A5 non-expressor genotype among the Orang Asli was unravelled and the findings in this study may serve as a guide for the optimisation of pharmacotherapy for the Orang Asli community.

    Matched MeSH terms: Genotype
  17. A118G mu opioid receptor polymorphism among drug addicts in Malaysia
    Nagaya D, Ramanathan S, Ravichandran M, Navaratnam V
    J Integr Neurosci, 2012 Mar;11(1):117-22.
    PMID: 22744787
    Drug addiction is an important social problem in many countries. Genetic and environmental factors contribute to the predisposition of drug addiction. Genetic variations at the μ opioid receptor (OPRM1) gene locus have been associated with opiate addiction. The present study aims to delineate the frequency of A118G allele of OPRM1 among Malaysian subjects. The frequency of A allele and G allele were 51% and 49%, respectively for addicts and about 73% and 27% respectively for healthy volunteers. The frequency of G allele was 1.77-fold higher in addicts by odds ratio calculation at 95% Cl, which indicate the G allele to be strongly associated with addiction X(2) = 15.31,P < 0.0001; odds ratio 2.51; 95% Cl (1.575-3.994), compared to healthy volunteers. A significant association was observed between A118G polymorphism in μ opioid receptor gene and drug addiction.
    Matched MeSH terms: Genotype
  18. ABCA1 gene polymorphisms and their associations with coronary artery disease and plasma lipids in males from three ethnic populations in Singapore
    Tan JH, Low PS, Tan YS, Tong MC, Saha N, Yang H, et al.
    Hum Genet, 2003 Jul;113(2):106-17.
    PMID: 12709788
    Mutations in the ATP-binding cassette transporter ABCA1 underlie Tangier disease and familial hypoalphaliproteinemia (FHA), disorders that are characterised by reduced high-density lipoprotein-cholesterol (HDL-C) concentration and cholesterol efflux, and increased coronary artery disease (CAD). We explored if polymorphisms in the ABCA1 gene are associated with CAD and variations in plasma lipid levels, especially HDL-C, and whether the associations may depend on ethnicity. Male cases and controls from the Singapore Chinese, Malay and Indian populations were genotyped for five ABCA1 single nucleotide polymorphisms. Various single-locus frequency distribution differences between cases and controls were detected in different ethnic groups: the promoter -14C>T in Indians, exon 18 M883I in Malays, and 3'-untranslated (UTR) region 8994A>G in Chinese. For the Malay population, certain haplotypes carrying the I825- A (exon 17) and M883- G alleles were more frequent among cases than controls, whereas the converse was true for the alternative configuration of V825- G and I883- A, and this association was reinforced in multi-locus disequilibrium analysis that utilized genotypic data. In the healthy controls, associations were found for -14C>T genotypes with HDL-C in Chinese; 237indelG (5'UTR) with apolipoprotein A1 (apoA1) in Malays and total cholesterol (TC) in Indians; M883I with lipoprotein(a) [Lp(a)] in Malays and apolipoprotein B (apoB) in Chinese; and 8994A>G with Lp(a) in Malays, and TC, low-density lipoprotein-cholesterol (LDL-C) as well as apoB in Indians. While genotype-phenotype associations were not reproduced across populations and loci, V825I and M883I were clearly associated with CAD status in Malays with no effects on HDL-C or apoA1.
    Matched MeSH terms: Genotype
  19. Fulltext ABCB1 C3435T polymorphism and the risk of resistance to antiepileptic drugs in epilepsy: a systematic review and meta-analysis
    Haerian BS, Roslan H, Raymond AA, Tan CT, Lim KS, Zulkifli SZ, et al.
    Seizure, 2010 Jul;19(6):339-46.
    PMID: 20605481 DOI: 10.1016/j.seizure.2010.05.004
    The C3435T, a major allelic variant of the ABCB1 gene, is proposed to play a crucial role in drug-resistance in epilepsy. The C/C genotype carriers reportedly are at higher risk of pharmacoresistance to AEDs, but only in some studies. The hypothesis of the C-variant associated risk and resistance to antiepileptic drugs (AEDs) has been hampered by conflicting results from inadequate power in case-control studies. To assess the role of C3435T polymorphism in drug-resistance in epilepsy, a systematic review and meta-analysis was conducted.
    Matched MeSH terms: Genotype
  20. ABCB1 Polymorphisms and Cold Pressor Pain Responses: Opioid-Dependent Patients on Methadone Maintenance Therapy
    Zahari Z, Lee CS, Ibrahim MA, Musa N, Mohd Yasin MA, Lee YY, et al.
    Nurs Res, 2017 Mar-Apr;66(2):134-144.
    PMID: 28252574 DOI: 10.1097/NNR.0000000000000204
    BACKGROUND: Methadone is a substrate of the P-glycoprotein efflux transporter, which is encoded by ABCB1 (MDR1), and thus, ABCB1 polymorphisms may influence the transport of methadone at the blood-brain barrier, affecting its adverse effects.

    OBJECTIVES: This study investigated the association between ABCB1 polymorphisms and cold pressor pain responses among opioid-dependent patients on methadone maintenance therapy (MMT).

    METHODS: Malay male opioid-dependent patients receiving MMT (n = 148) were recruited. Cold pressor pain responses (pain threshold, pain tolerance, and pain intensity) were measured at 0, 2, 4, 8, 12, and 24 hours post-methadone dose. DNA was extracted from whole blood and genotyped for ABCB1 polymorphisms including 1236C>T (rs1128503), 2677G>T/A (rs2032582), and 3435C>T (rs1045642) using the allelic discrimination real-time polymerase chain reaction. Repeated-measure analysis of variance between-group analysis was used to compare the three cold pressor pain responses and ABCB1 polymorphisms (1236C>T, 2677G>T/A, and 3435C>T) according to genotypes and allelic additive models, genotype dominant and recessive models, haplotypes, and diplotypes.

    RESULTS: Patients with 2677 GG or 2677G allele had the lowest pain threshold compared with 2677G>T/A genotypes or alleles (p = .007 and .002, respectively). Haplotype analysis showed a significant association between ABCB1 haplotypes and pain threshold (p = .02). Patients with 2677G allele had the lowest pain tolerance compared to those with 2677T and 2677A alleles (2677G < 2677T < 2677A allele carriers; p = .05). In terms of pain intensity scores, patients with 2677 GG or 2677G allele had the highest scores compared to other 2677G>T/A genotypes or alleles (p = .04 and .008, respectively). Haplotype analysis revealed a significant difference between patients with CGC haplotype and those without this haplotype (p = .02).

    DISCUSSION: To the best of our knowledge, this study provides the first evidence that ABCB1 polymorphisms are associated with cold pressor pain responses among Malay male patients with opioid dependence on MMT. The results may provide an initial prediction on heightened pain sensitivity or hyperalgesia for individuals who are carriers of the ABCB1 polymorphisms.
    Matched MeSH terms: Genotype
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