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Fulltext XPC Lys939Gln polymorphism, smoking and risk of sporadic colorectal cancer among Malaysians

Ahmad Aizat AA, Siti Nurfatimah MS, Aminudin MM, Ankathil R

World J Gastroenterol, 2013 Jun 21;19(23):3623-8.
PMID: 23801864 DOI: 10.3748/wjg.v19.i23.3623

To investigate the risk association of xeroderma pigmentosum group C (XPC) Lys939Gln polymorphism alone and in combination with cigarette smoking on colorectal cancer (CRC) predisposition.

Matched MeSH terms: Gene Frequency
Fulltext Complete molecular characterisation of glucose-6-phosphate dehydrogenase (G6PD) deficiency in a group of Malaysian Chinese neonates

Ainoon O, Boo NY, Yu YH, Cheong SK, Hamidah HN, Lim JH

Malays J Pathol, 2004 Dec;26(2):89-98.
PMID: 16329560

We performed DNA analysis on cord blood samples of 128 Chinese male neonates diagnosed as G6PD deficiency in Hospital Universiti Kebangsaan Malaysia by a combination PCR-restriction enzyme digest technique, Single Stranded Conformation Polymorphism analysis and DNA sequencing. We found 10 different G6PD-deficient mutations exist. The two commonest alleles were G6PD Canton 1376 G>T (42.3%) and Kaiping 1388 G>A (39.4%) followed by G6PD Gaohe 592 G>A (7.0%), Chinese-5 1024 C>T, Nankang 517 T>C (1.5%), Mahidol 487 G>A (1.6%), Chatham 1003 G>T (0.8%), Union 1360 C>T (0.8%), Viangchan 871 G>A (0.8%) and Quing Yang 392 G>T (0.8%). Sixty eight percent (88/125) neonates in this study had neonatal jaundice and 29.7% developed hyperbilirubinemia >250 micromol/l. The incidence of hyperbilirubinemia >250 micromol/l was higher in G6PD Kaiping (43.8%) than G6PD Canton (22%) (p< 0.05). There was no significant difference in the incidence of neonatal jaundice, mean serum bilirubin, mean age for peak serum bilirubin, percentage of babies requiring phototherapy and mean duration of phototherapy between the two major variants. None of the 88 neonates required exchange transfusion. In conclusion we have completely characterized the molecular defects of a group of Chinese G6PD deficiency in Malaysia. The mutation distribution reflects the original genetic pool and limited ethnic admixture with indigenous Malays.

Matched MeSH terms: Gene Frequency
Glucose-6-phosphate dehydrogenase (G6PD) variants in Malaysian Malays

Ainoon O, Yu YH, Amir Muhriz AL, Boo NY, Cheong SK, Hamidah NH

Hum Mutat, 2003 Jan;21(1):101.
PMID: 12497642 DOI: 10.1002/humu.9103

We performed DNA analysis using cord blood samples on 86 male Malay neonates diagnosed as G6PD deficiency in the National University of Malaysia Hospital by a combination of rapid PCR-based techniques, single-stranded conformation polymorphism analysis (SSCP) and DNA sequencing. We found 37.2% were 871G>A (G6PD Viangchan), 26.7% were nt 563 C>T (G6PD Mediterranean) and 15.1% were 487G>A (G6PD Mahidol) followed by 4.7% 1376G>T (G6PD Canton), 3.5% 383T>C (G6PD Vanua Lava), 3.5% 592C>T (G6PD Coimbra), 2.3% 1388G>A (G6PD Kaiping), 2.3% 1360C>T (G6PD Union), 2.3% 1003G>A (G6PD Chatham), 1.2% 131C>G (G6PD Orissa) and 1.2% 1361G>A (G6PD Andalus). Seventy-one (82.6%) of the 86 G6PD-deficient neonates had neonatal jaundice. Fifty seven (80%) of the 71 neonates with jaundice required phototherapy with only one neonate progressing to severe hyperbilirubinemia (serum bilirubin >340 micromol/l) requiring exchange transfusion. There was no significant difference in the incidence of neonatal jaundice, mean serum bilirubin level, mean age for peak serum bilirubin, percentage of babies requiring phototherapy and mean number of days of phototherapy between the three common variants. In conclusion, the molecular defects of Malay G6PD deficiency is heterogeneous and G6PD Viangchan, Mahidol and Mediterranean account for at least 80% of the cases. Our findings support the observation that G6PD Viangchan and Mahidol are common Southeast Asian variants. Their presence in the Malays suggests a common ancestral origin with the Cambodians, Laotians and Thais. Our findings together with other preliminary data on the presence of the Mediterranean variant in this region provide evidence of strong Arab influence in the Malay Archipelago.

Matched MeSH terms: Gene Frequency
Fulltext Association of Arg72Pro of P53 polymorphism with colorectal cancer susceptibility risk in Malaysian population

Aizat AA, Shahpudin SN, Mustapha MA, Zakaria Z, Sidek AS, Abu Hassan MR, et al.

Asian Pac J Cancer Prev, 2011;12(11):2909-13.
PMID: 22393962

BACKGROUND: Colorectal cancer (CRC) results from the interaction between environmental exposures and genetic predisposition factors.

AIMS: A case control study was designed and to investigate the genotype frequencies of P53Arg72Pro polymorphism in Malaysian CRC patients and healthy controls and to determine the associated risk of this polymorphism with CRC predisposition.

METHODS: In this case-control study, peripheral blood samples of 202 sporadic CRC patients and 201 normal controls were collected, DNA extracted and genotyped using the polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP) technique.

RESULTS: Genotype analysis showed the frequency of homozygous variant (Pro/Pro) genotype (21%) to be significantly higher in cases compared to controls (13%), (p=0.013). On examining the association between variant genotypes and CRC risk, the Pro/Pro homozygous variant genotype showed significantly higher risk association with CRC susceptibility (OR: 2.047, CI: 1.063-4.044, p=0.033). When stratified according to age, we observed that, individuals aged above 50 years and carriers of pro/pro genotype had significantly higher risk with OR: 3.642, CI: 1.166-11.378, p=0.026.

CONCLUSIONS: Our results suggest that the codon 72 SNP which results in amino acid substitution of Arginine to Proline in cell cycle regulatory gene P53, is associated with sporadic CRC risk and carriers of Pro/Pro genotype and more than 50 years old may have high susceptibility.

Matched MeSH terms: Gene Frequency
Fulltext Analysis of the Origin of Emiratis as Inferred from a Family Study Based on HLA-A, -C, -B, -DRB1, and -DQB1 Genes

Al Yafei Z, Hajjej A, Alvares M, Al Mahri A, Nasr A, Mirghani R, et al.

Genes (Basel), 2023 May 26;14(6).
PMID: 37372339 DOI: 10.3390/genes14061159

In this study, we investigated HLA class I and class II allele and haplotype frequencies in Emiratis and compared them to those of Asian, Mediterranean, and Sub-Saharan African populations.
METHODS: Two-hundred unrelated Emirati parents of patients selected for bone marrow transplantation were genotyped for HLA class I (A, B, C) and class II (DRB1, DQB1) genes using reverse sequence specific oligonucleotide bead-based multiplexing. HLA haplotypes were assigned with certainty by segregation (pedigree) analysis, and haplotype frequencies were obtained by direct counting. HLA class I and class II frequencies in Emiratis were compared to data from other populations using standard genetic distances (SGD), Neighbor-Joining (NJ) phylogenetic dendrograms, and correspondence analysis.
RESULTS: The studied HLA loci were in Hardy-Weinberg Equilibrium. We identified 17 HLA-A, 28 HLA-B, 14 HLA-C, 13 HLA-DRB1, and 5 HLA-DQB1 alleles, of which HLA-A*02 (22.2%), -B*51 (19.5%), -C*07 (20.0%), -DRB1*03 (22.2%), and -DQB1*02 (32.8%) were the most frequent allele lineages. DRB1*03~DQB1*02 (21.2%), DRB1*16~DQB1*05 (17.3%), B*35~C*04 (11.7%), B*08~DRB1*03 (9.7%), A*02~B*51 (7.5%), and A*26~C*07~B*08~DRB1*03~DQB1*02 (4.2%) were the most frequent two- and five-locus HLA haplotypes. Correspondence analysis and dendrograms showed that Emiratis were clustered with the Arabian Peninsula populations (Saudis, Omanis and Kuwaitis), West Mediterranean populations (North Africans, Iberians) and Pakistanis, but were distant from East Mediterranean (Turks, Albanians, Greek), Levantine (Syrians, Palestinians, Lebanese), Iranian, Iraqi Kurdish, and Sub-Saharan populations.
CONCLUSIONS: Emiratis were closely related to Arabian Peninsula populations, West Mediterranean populations and Pakistanis. However, the contribution of East Mediterranean, Levantine Arab, Iranian, and Sub-Saharan populations to the Emiratis' gene pool appears to be minor.

Matched MeSH terms: Gene Frequency/genetics
Contributions of IKZF1, DDC, CDKN2A, CEBPE, and LMO1 Gene Polymorphisms to Acute Lymphoblastic Leukemia in a Yemeni Population

Al-Absi B, Razif MFM, Noor SM, Saif-Ali R, Aqlan M, Salem SD, et al.

Genet Test Mol Biomarkers, 2017 Oct;21(10):592-599.
PMID: 28768142 DOI: 10.1089/gtmb.2017.0084

BACKGROUND: Genome-wide and candidate gene association studies have previously revealed links between a predisposition to acute lymphoblastic leukemia (ALL) and genetic polymorphisms in the following genes: IKZF1 (7p12.2; ID: 10320), DDC (7p12.2; ID: 1644), CDKN2A (9p21.3; ID: 1029), CEBPE (14q11.2; ID: 1053), and LMO1 (11p15; ID: 4004). In this study, we aimed to conduct an investigation into the possible association between polymorphisms in these genes and ALL within a sample of Yemeni children of Arab-Asian descent.
METHODS: Seven single-nucleotide polymorphisms (SNPs) in IKZF1, three SNPs in DDC, two SNPs in CDKN2A, two SNPs in CEBPE, and three SNPs in LMO1 were genotyped in 289 Yemeni children (136 cases and 153 controls), using the nanofluidic Dynamic Array (Fluidigm 192.24 Dynamic Array). Logistic regression analyses were used to estimate ALL risk, and the strength of association was expressed as odds ratios with 95% confidence intervals.
RESULTS: We found that the IKZF1 SNP rs10235796 C allele (p = 0.002), the IKZF1 rs6964969 A>G polymorphism (p = 0.048, GG vs. AA), the CDKN2A rs3731246 G>C polymorphism (p = 0.047, GC+CC vs. GG), and the CDKN2A SNP rs3731246 C allele (p = 0.007) were significantly associated with ALL in Yemenis of Arab-Asian descent. In addition, a borderline association was found between IKZF1 rs4132601 T>G variant and ALL risk. No associations were found between the IKZF1 SNPs (rs11978267; rs7789635), DDC SNPs (rs3779084; rs880028; rs7809758), CDKN2A SNP (rs3731217), the CEBPE SNPs (rs2239633; rs12434881) and LMO1 SNPs (rs442264; rs3794012; rs4237770) with ALL in Yemeni children.
CONCLUSION: The IKZF1 SNPs, rs10235796 and rs6964969, and the CDKN2A SNP rs3731246 (previously unreported) could serve as risk markers for ALL susceptibility in Yemeni children.

Matched MeSH terms: Gene Frequency
Differences in allele frequencies of autosomal dominant hypercholesterolemia SNPs in the Malaysian population

Alex L, Chahil JK, Lye SH, Bagali P, Ler LW

J Hum Genet, 2012 Jun;57(6):358-62.
PMID: 22534770 DOI: 10.1038/jhg.2012.34

Hypercholesterolemia is caused by different interactions of lifestyle and genetic determinants. At the genetic level, it can be attributed to the interactions of multiple polymorphisms, or as in the example of familial hypercholesterolemia (FH), it can be the result of a single mutation. A large number of genetic markers, mostly single nucleotide polymorphisms (SNP) or mutations in three genes, implicated in autosomal dominant hypercholesterolemia (ADH), viz APOB (apolipoprotein B), LDLR (low density lipoprotein receptor) and PCSK9 (proprotein convertase subtilisin/kexin type-9), have been identified and characterized. However, such studies have been insufficiently undertaken specifically in Malaysia and Southeast Asia in general. The main objective of this study was to identify ADH variants, specifically ADH-causing mutations and hypercholesterolemia-associated polymorphisms in multiethnic Malaysian population. We aimed to evaluate published SNPs in ADH causing genes, in this population and to report any unusual trends. We examined a large number of selected SNPs from previous studies of APOB, LDLR, PCSK9 and other genes, in clinically diagnosed ADH patients (n=141) and healthy control subjects (n=111). Selection of SNPs was initiated by searching within genes reported to be associated with ADH from known databases. The important finding was 137 mono-allelic markers (44.1%) and 173 polymorphic markers (55.8%) in both subject groups. By comparing to publicly available data, out of the 137 mono-allelic markers, 23 markers showed significant differences in allele frequency among Malaysians, European Whites, Han Chinese, Yoruba and Gujarati Indians. Our data can serve as reference for others in related fields of study during the planning of their experiments.

Matched MeSH terms: Gene Frequency*
Fulltext The genetic architecture of the MHC class II region in British Texel sheep

Ali AO, Stear A, Fairlie-Clarke K, Brujeni GN, Isa NM, Salisi MS, et al.

Immunogenetics, 2017 03;69(3):157-163.
PMID: 27921144 DOI: 10.1007/s00251-016-0962-6

Understanding the structure of the major histocompatibility complex, especially the number and frequency of alleles, loci and haplotypes, is crucial for efficient investigation of the way in which the MHC influences susceptibility to disease. Nematode infection is one of the most important diseases suffered by sheep, and the class II region has been repeatedly associated with differences in susceptibility and resistance to infection. Texel sheep are widely used in many different countries and are relatively resistant to infection. This study determined the number and frequency of MHC class II genes in a small flock of Texel sheep. There were 18 alleles at DRB1, 9 alleles at DQA1, 13 alleles at DQB1, 8 alleles at DQA2 and 16 alleles at DQB2. Several haplotypes had no detectable gene products at DQA1, DQB1 or DQB2, and these were defined as null alleles. Despite the large numbers of alleles, there were only 21 distinct haplotypes in the population. The relatively small number of observed haplotypes will simplify finding disease associations because common haplotypes provide more statistical power but complicate the discrimination of causative mutations from linked marker loci.

Matched MeSH terms: Gene Frequency
The pattern of HLA-A, -B and -DRB1 alleles and haplotypes of four Malay sub-ethnic groups namely Kelantan, Champa, Patani and Mandailing Malays of Peninsular Malaysia

Allia S, Norazmi MN, Panneerchelvam S, Zafarina Z

Hum Immunol, 2019 Jul;80(7):423-424.
PMID: 30836128 DOI: 10.1016/j.humimm.2019.02.015

"Bumiputra" or "son of the soil" is a term used to represent the Malays and other indigenous populations of Malaysia. The Malays are Austronesian speaking population and originated from different parts of the Indo-Malay Archipelago. The migration of Malay population from different parts of Indo-Malay Archipelago were mainly due to trading purposes which shaped the current Malay sub-ethnic groups with unique culture and with distinctive dialects. In this study, HLA typing was carried out using Sequence-based Typing (SBT) method on 109 individuals comprising of four Malay sub-ethnic groups namely Kelantan (n = 28), Champa (n = 29), Patani (n = 25) and Mandailing (n = 27) Malays. The HLA data is available in the Allele Frequencies Net Database (AFND).

Matched MeSH terms: Gene Frequency
Fulltext The Use of SNPs in Pharmacogenomics Studies

Alwi ZB

Malays J Med Sci, 2005 Jul;12(2):4-12.
PMID: 22605952

Pharmacogenomics is the study of how genetic makeup determines the response to a therapeutic intervention. It has the potential to revolutionize the practice of medicine by individualisation of treatment through the use of novel diagnostic tools. This new science should reduce the trial-and-error approach to the choice of treatment and thereby limit the exposure of patients to drugs that are not effective or are toxic for them. Single Nucleotide Polymorphisms (SNPs) holds the key in defining the risk of an individual's susceptibility to various illnesses and response to drugs. There is an ongoing process of identifying the common, biologically relevant SNPs, in particular those that are associated with the risk of disease. The identification and characterization of large numbers of these SNPs are necessary before we can begin to use them extensively as genetic tools. As SNP allele frequencies vary considerably across human ethnic groups and populations, the SNP consortium has opted to use an ethnically diverse panel to maximize the chances of SNP discovery. Currently most studies are biased deliberately towards coding regions and the data generated from them therefore are unlikely to reflect the overall distribution of SNPs throughout the genome. The SNP consortium protocol was designed to identify SNPs without any bias towards these coding regions. Most pharmacogenomic studies were carried out in heterogeneous clinical trial populations, using case-control or cohort association study designs employing either candidate gene or Linkage disequilibrium (LD) mapping approaches. Concerns about the required patient sample sizes, the extent of LD, the number of SNPs needed in a map, the cost of genotyping SNPs, and the interpretation of results are some of the challenges that surround this field. While LD mapping is appealing in that it is an unbiased approach and allows a comprehensive genome-wide survey, the challenges and limitations are significant. An alternative such as the candidate gene approach does offer several advantages over LD mapping. Ultimately, as all human genes are discovered, the need for random SNP markers diminishes and gene-based SNP approaches will predominate. The challenges will then be to demonstrate convincing links between genetic variation and drug responses and to translate that information into useful pharmacogenomic tests.

Matched MeSH terms: Gene Frequency
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: Gene Frequency*
STR data for the 13 CODIS loci in Singapore Malays

Ang HC, Sornarajah R, Lim SE, Syn CK, Tan-Siew WF, Chow ST, et al.

Forensic Sci Int, 2005 Mar 10;148(2-3):243-5.
PMID: 15639622

Allele frequencies for the 13 CODIS (Combined DNA Index System, USA) STR loci included in the AmpFISTR Profiler Plus and AmpFISTR Cofiler kits (Applied Biosystems, Foster City, USA) were determined in a sample of 197 unrelated Malays in Singapore.

Matched MeSH terms: Gene Frequency*
Fulltext Genetic analysis of the M2/ANXA5 haplotype as recurrent pregnancy loss predisposition in the Malay population

Ang KC, Kathirgamanathan S, Ch'ng ES, Lee YY, Roslani AL, Naidu B, et al.

J Assist Reprod Genet, 2017 Apr;34(4):517-524.
PMID: 28108842 DOI: 10.1007/s10815-017-0871-0

PURPOSE: The aim of this study was to evaluate a new predisposition factor, M2/ANXA5 (RPRGL3), in recurrent pregnancy loss (RPL) patients of Malay origin, since it was previously known that the prevalence of this condition is relatively high among the Malay population of Malaysia, where conventional hereditary thrombophilia factors have been generally ruled out.
METHODS: A total of 232 women who had experienced ≥2 unexplained RPL and 141 available male partners were recruited, with 360 healthy Malay and 166 parous female controls. Prevalence of M2 carriage and RPL odds ratios were calculated in (a) control and patient groups; (b) clinically defined subgroups in categories of pregnancy loss, primary, secondary, and tertiary; and (c) timing of pregnancy loss in early, ≤15th gestation week and "late" fetal losses, and >15th gestation week subgroups.
RESULTS: Both male and female subjects had similar M2/ANXA5 allele frequencies. The carrier rate of M2/ANXA5 for the general Malay population was 42.2 and 34.9% for parous controls. These carrier rates compared to Malay RPL subjects (52% M2 carriers) resulted in elevated odds ratios (95% confidence interval) of 1.53 (1.1 to 2.1) and 1.97 (1.3 to 3.1) accordingly for early fetal losses. Moreover, exceeding copy numbers of M2/ANXA5 alleles seemed to afflict a greater chance of RPL in couples, especially when both partners were M2 carriers.
CONCLUSION: This study confirmed the proposed role of M2/ANXA5 as embryonic, genetically associated thrombophilia predisposition factor for early RPL among ethnic Malay of Malaysia.

Matched MeSH terms: Gene Frequency/genetics
Association of ADIPOQ gene with obesity and adiponectin levels in Malaysian Malays

Apalasamy YD, Rampal S, Salim A, Moy FM, Bulgiba A, Mohamed Z

Mol Biol Rep, 2014 May;41(5):2917-21.
PMID: 24449366 DOI: 10.1007/s11033-014-3147-0

Studies have shown that single-nucleotide polymorphisms (SNPs) on the ADIPOQ gene have been linked with obesity and with adiponectin levels in various populations. Here, we aimed to investigate the association of ADIPOQ rs17366568 and rs3774261 SNPs with obesity and with adiponectin levels in Malaysian Malays. Obesity parameters and adiponectin levels were measured in 574 subjects. Genotyping was performed using real-time polymerase chain reaction and Sequenom MassARRAY. A significant genotypic association was observed between ADIPOQ rs17366568 and obesity. The frequencies of AG and AA genotypes were significantly higher in the obese group (11%) than in the non-obese group (5%) (P=0.024). The odds of A alleles occurring among the obese group were twice those among the non-obese group (odds ratio 2.15; 95% confidence interval 1.13-4.09). However, no significant association was found between allelic frequencies of ADIPOQ rs17366568 and obesity after Bonferroni correction (P>0.025) or between ADIPOQ rs3774261 and obesity both at allelic and genotypic levels. ADIPOQ SNPs were not significantly associated with log-adiponectin levels. GA, GG, and AG haplotypes of the ADIPOQ gene were not associated with obesity. We confirmed the previously reported association of ADIPOQ rs17366568 with the risk of obesity. ADIPOQ SNPs are not important modulators of adiponectin levels in this population.

Matched MeSH terms: Gene Frequency
Fulltext Interleukin 1β (+3954; -511) Genotype Polymorphism and its Association with Severe Chronic Generalized Periodontitis in the Malaysian Population

Arora S, Ramachandra SS, Abdullah F, Gundavarapu KC

Contemp Clin Dent, 2017 Jan-Mar;8(1):102-105.
PMID: 28566859 DOI: 10.4103/ccd.ccd_1177_16

INTRODUCTION: Single-nucleotide polymorphisms (SNPs) in interleukin 1β (IL-1β) gene have been known to be associated with increased susceptibility to chronic periodontitis among various ethnic populations. SNPs are more commonly observed at loci + 3954 and - 511. The aim of this study was to evaluate the role of IL-1β gene polymorphism at loci +3954 and - 511, and its association with severe chronic generalized periodontitis among the ethnic Malay, Chinese, and Indians within the Malaysian population.

MATERIALS AND METHODS: Saliva samples from 120 subjects (60 cases and 60 controls) in the age group of 25-50 years were collected for isolation of genetic material using Norgen technique. Clinical attachment loss of ≥5 mm was considered as severe chronic generalized periodontitis. SNP's at loci +3954 and - 511 were identified and analyzed using Kompetitive Allele Specific Polymerase Chain Reaction Genotyping System (KASP™). Differences in the allele/genotype frequencies were assessed by Chi-square test (P < 0.05).

RESULTS: On the comparison between cases and controls of IL-1β genotype polymorphism (+3954 and - 511), the difference in the genotype frequencies was statistically insignificant in all the three ethnicities. The genotype frequency in both groups in all three ethnicities of the Malaysian population was similar.

CONCLUSION: IL-1β genotype polymorphism at +3954 and - 511 was found to be not associated with severe chronic generalized periodontitis among the three ethnicities in Malaysia. Studies with larger sample size should be done to confirm the findings of this study.

Matched MeSH terms: Gene Frequency
The impact of APOA5, APOB, APOC3 and ABCA1 gene polymorphisms on ischemic stroke: Evidence from a meta-analysis

Au A, Griffiths LR, Irene L, Kooi CW, Wei LK

Atherosclerosis, 2017 Oct;265:60-70.
PMID: 28865324 DOI: 10.1016/j.atherosclerosis.2017.08.003

BACKGROUND AND AIMS: Genetic studies have been reported on the association between APOA5, APOB, APOC3 and ABCA1 gene polymorphisms and ischemic stroke, but results remain controversial. Hence, this meta-analysis aimed to infer the causal relationships of APOA5 (rs662799, rs3135506), APOB (rs693, rs1042031, rs1801701), APOC3 (rs4520, rs5128, rs2854116, rs2854117) and ABCA1 rs2230806 with ischemic stroke risk.
METHODS: A systematic review was performed for all the articles retrieved from multiple databases, up until March 2017. Data were extracted from all eligible studies, and meta-analysis was carried out using RevMan 5.3 and R package 3.2.1. The strength of association between each studied polymorphism and ischemic stroke risk was measured as odds ratios (ORs) and 95% confidence intervals (CIs), under fixed- and random-effect models.
RESULTS: A total of 79 studies reporting on the association between the studied polymorphisms and ischemic stroke risk were identified. The pooled data indicated that all genetic models of APOA5 rs662799 (ORs = 1.23-1.43), allelic and over-dominant models of APOA5 rs3135506 (ORs = 1.77-1.97), APOB rs1801701 (ORs = 1.72-2.13) and APOB rs1042031 (ORs = 1.66-1.88) as well as dominant model of ABCA1 rs2230806 (OR = 1.31) were significantly associated with higher risk of ischemic stroke. However, no significant associations were observed between ischemic stroke and the other five polymorphisms, namely ApoB (rs693) and APOC3 (rs4520, rs5128, rs2854116 and rs2854117), under any genetic model.
CONCLUSIONS: The present meta-analysis confirmed a significant association of APOA5 rs662799 CC, APOA5 rs3135506 CG, APOB rs1801701 GA, APOB rs1042031 GA and ABCA1 rs2230806 GG with increased risk of ischemic stroke.

Matched MeSH terms: Gene Frequency
Fulltext Association of the tumor necrosis factor alpha gene polymorphism with susceptibility and clinical-immunological findings of systemic lupus erythematosus

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: Gene Frequency
Fulltext The association of the HLA class II antigens with clinical and autoantibody expression in Malaysian Chinese patients with systemic lupus erythematosus

Azizah MR, Ainoi SS, Kuak SH, Kong NCT, Normaznah Y, Rahim MN

Asian Pac J Allergy Immunol, 2001 Jun;19(2):93-100.
PMID: 11699726

The frequency of the HLA class II antigens/alleles (HLA-DR, DQ and DP) were studied in 70 Malaysian Chinese patients with systemic lupus erythematosus (SLE) to examine the contribution of these genes to disease susceptibility, their clinical expression and Immunological responses. This was done using modified PCR-RFLP technique. These samples were then compared with 66 ethnically matched controls. We found a strong association of the DQA1*0102 (p corr = 0.032, rr = 3.39), DQB1*0501 (p corr = 0.003, rr = 4.55), *0601 (p corr = 0.006, rr = 4.22) and DPB1* 0901(p corr = 0.02, rr = 4.58) with SLE. Clinically, we found a strong association of DR2 and DQA1*0301 with renal involvement and DQA1*0102 with alopecia. Immunologically, statistical analysis (Chi-square test ) showed a strong association of DQA1*0102 with anti-Ro/La antibodies while DQA1*0301 was observed to be strongly associated with antibodies to ds DNA. DQA1*0102 was found more frequently in those with a later disease onset (30 years of age or above). From these data we suggest that the HLA class II genes play a role in conferring disease susceptibility and clinical and immunological expression.
Study site: SLE clinics, Pusat Perubatan Universiti Kebangsaan Malaysia (PPUKM), Kuala Lumpur, Malaysia

Matched MeSH terms: Gene Frequency/genetics; Gene Frequency/immunology
Class II HLA-DR antigen and DQA, DQB and DPB allele frequencies in Malay patients with systemic lupus erythematosus

Azizah MR, Ainol SS, Kuak SH, Kong NCT, Normaznah Y, Rahim MN

International Medical Journal (Tokyo), 2001;8(2):125-130.

Objective: The frequency of the HLA class II antigens (HLA DR, DQ and DP) were determined among Malay patients with systemic lupus erythematosus (SLE) to ascertain the role they play in disease susceptibility. Study design: Fifty-six Malay SLE patients on follow-up at the SLE Clinic of the National University of Malaysia Hospital, Kuala Lumpur were enrolled into the study. Controls were taken from healthy unrelated individuals, ethnically-matched. Materials and Methods: Five ml of anticoagulated blood was taken from each patient and control and DNA extracted. The HLADR, DQ and DP antigen/allele frequencies were determined by the technique of modified PCR-RFLP and statistical analysis done by Chi-square and Fischers exact test. Relative risk was determined by the odds ratio and significant p values were corrected for the number of antigens/alleles tested. Results: We found that the DR2 antigen was significantly increased among the patients (85.7%) as compared to controls (61%)(p corr=0.03, RR=3.83). As for HLA-DQA1, the allele most commonly found among the patients was *0102 (57 vs 49.2%). HLA-DQA1* 0601 was slightly decreased among the patients but this finding was insignificant. Both HLA-DQB1*0501 and 0601 were found to be increased among the patients even after correction of multiple comparisons made (p=0.0036, RR=4.56 and p=0.0048, RR=6.0, respectively). However, HLA-DQB1*0503 and 0301 was slightly decreased in the sle patients though not statistically significant. The frequency of HLA-DQB1*0201 was insignificantly increased among the patients. Limited studies on the DPB1 locus shows the uncertain role of this antigen in contributing to disease susceptibility. However, our analysis of the HLA-DPB1*0901 showed a slight increase among the patients as compared to controls but failed to remain significant after being corrected with number of comparisons made. All other HLA-DPB1 alleles exhibited similar frequencies between sle patients and controls. Conclusion: From this study we suggest that HLA DR2, DQB1*0501 and *0601 may be important genetic factors in conferring disease susceptibility in the Malay SLE population of Malaysia.

Matched MeSH terms: Gene Frequency
Genetic factors and malaria in the Temuan

Baer A, Lie-Injo LE, Welch QB, Lewis AN

Am J Hum Genet, 1976 Mar;28(2):179-88.
PMID: 817597

The jungle habitat of the Temuan aborigines harbors a variety of infectious diseases, the most notable being malaria. Our study of 15 genetic systems in the Temuan revealed substantial polymorphism and within-population genetic diversity. The polymorphisms for Hb beta, G6PD, and El are of interest in regard to genetic adaptation to malaria. Among the polymorphisms investigated we conclude that G6PD deficiency and elliptocytosis are likely to have malaria-resistant effects as evidenced by their low association with malarial parasitemia or their higher frequency in adults than in children. These findings suggest that the malarial habitat of the Temuans is livable in the long range sense for them because of the cluster of malaria-resistant alleles in their gene pool (G6PD)-, El, and possibly, but not tested here because of its low frequency, Hb beta E). The same condition probably holds for the Semai, the nearest aborigine neighbors of the Temuan (although the Semai have not been tested for malarial parasitemia and for these polymorphisms simultaneously), since the Semai have substantial Hb betaE, G6PD-, and El. The Temuan have a cultural identity system of rituals, beliefs, and certain aspects of language which effectively isolates them genetically from Malays and other nonaborigines. This system hinders the dilution of the malaria-resistant alleles of the Temuan gene pool with the malaria-susceptible alleles of the nonaborigine gene pools.

Matched MeSH terms: Gene Frequency*

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