Central Asia and the Indian subcontinent represent an area considered as a source and a reservoir for human genetic diversity, with many markers taking root here, most of which are the ancestral state of eastern and western haplogroups, while others are local. Between these two regions, Terai (Nepal) is a pivotal passageway allowing, in different times, multiple population interactions, although because of its highly malarial environment, it was scarcely inhabited until a few decades ago, when malaria was eradicated. One of the oldest and the largest indigenous people of Terai is represented by the malaria resistant Tharus, whose gene pool could still retain traces of ancient complex interactions. Until now, however, investigations on their genetic structure have been scarce mainly identifying East Asian signatures.
Matched MeSH terms: Asian Continental Ancestry Group/genetics
Killer cell immunoglobulin-like receptors (KIR) gene frequencies have been shown to be distinctly different between populations and contribute to functional variation in the immune response. We have investigated KIR gene frequencies in 370 individuals representing three Asian populations in Singapore and report here the distribution of 14 KIR genes (2DL1, 2DL2, 2DL3, 2DL4, 2DL5, 2DS1, 2DS2, 2DS3, 2DS4, 2DS5, 3DL1, 3DL2, 3DL3, 3DS1) with two pseudogenes (2DP1, 3DP1) among Singapore Chinese (n = 210); Singapore Malay (n = 80), and Singapore Indian (n = 80). Four framework genes (KIR3DL3, 3DP1, 2DL4, 3DL2) and a nonframework pseudogene 2DP1 were detected in all samples while KIR2DS2, 2DL2, 2DL5, and 2DS5 had the greatest significant variation across the three populations. Fifteen significant linkage patterns, consistent with associations between genes of A and B haplotypes, were observed. Eighty-four distinct KIR profiles were determined in our populations, 38 of which had not been described in other populations. KIR haplotype studies were performed using nine Singapore Chinese families comprising 34 individuals. All genotypes could be resolved into corresponding pairs of existing haplotypes with eight distinct KIR genotypes and eight different haplotypes. The haplotype A2 with frequency of 63.9% was dominant in Singapore Chinese, comparable to that reported in Korean and Chinese Han. The A haplotypes predominate in Singapore Chinese, with ratio of A to B haplotypes of approximately 3:1. Comparison with KIR frequencies in other populations showed that Singapore Chinese shared similar distributions with Chinese Han, Japanese, and Korean; Singapore Indian was found to be comparable with North Indian Hindus while Singapore Malay resembled the Thai.
Matched MeSH terms: Asian Continental Ancestry Group/genetics*
To evaluate the association between body mass index (BMI) and health-related quality of life (HRQoL) in a multiethnic Asian population in Singapore, and to explore if the World Health Organization (WHO) recommendation of alternative BMI cutoffs for Asians could be further strengthened by evidence of higher risk of impaired HRQoL using these criteria.
Matched MeSH terms: Asian Continental Ancestry Group*
A novel human leukocyte antigen-B allele officially named B*3589, was found in an indigenous individual of Jehai ethnicity when sequencing was performed to investigate human genome variation in a research project. B*3589 differs form B*3505 in a point mutation at codon 169 (CGC to TGC) resulting in an amino acid change from Arg to Cys.
Matched MeSH terms: Asian Continental Ancestry Group/genetics
Angiotensin II type 1 receptor (AGT1R) gene 1166A > C polymorphism has been shown to be associated with essential hypertension and aortic stiffness as measured by carotid femoral pulse wave velocity (PWV). This study was carried out to investigate the association of the 1166A > C polymorphism with blood pressure (BP) and PWV among Malay hypertensive and normotensive subjects. Two hundred and one hypertensive subjects without evidence of cardiovascular (CV) complications and 201 age- and sex-matched normotensive subjects were studied in a cross-sectional design. Blood pressures (BP) and PWV were measured, and 1166A > C genotype was determined by polymerase chain reaction followed by restriction enzyme digestion. The 1166C allele frequency was 7.96% and 7.73% among Malay hypertensive and normotensive subjects, respectively. There was no association of the 1166A > C polymorphism with BP in the hypertensive, normotensive or overall Malay populations. PWV was significantly higher among 1166C allele carriers as compared to non-carriers (10.52 +/- 1.82 vs. 10.15 +/- 1.80, p = 0.040) in the overall population, but not in the hypertensive and normotensive populations separately. In conclusion, the frequency of 1166C polymorphism is similar among Malay hypertensive and normotensive subjects. This polymorphism has no association with BP but may have an influence on PWV in Malays, which needs further investigation.
Matched MeSH terms: Asian Continental Ancestry Group/genetics*
To determine the values for the anterior best-fit sphere (BFS) and posterior BFS in an Asian population using the Orbscan II (Bausch & Lomb) slit-scanning Placido disk corneal topographer.
Matched MeSH terms: Asian Continental Ancestry Group/ethnology*
The aims of this study were to examine the prevalence and severity of aggression in patients with first-episode psychosis and to identify the association between aggression and sociodemographic and clinical factors.
Matched MeSH terms: Asian Continental Ancestry Group/ethnology
The use of STR multiplexes with the incorporated gender marker Amelogenin is common practice in forensic DNA analysis. However, when a known male sample shows a dropout of the Amelogenin Y-allele, the STR system falsely genotypes it as a female. To date, our laboratory has observed 18 such cases: 12 from our Y-STR database and six from casework. A study on 980 male individuals in the Malaysian population using the AmpFlSTR Y-filer has revealed a distinct Y-chromosome haplotype associated with the Amelogenin nulls. Our results showed that whilst the Amelogenin nulls were noticeably absent among the Chinese, both the Indians and Malays exhibited such mutations at 3.2 and 0.6%, respectively. It was also found that the Amelogenin negative individuals predominantly belonged to the J2e lineage, suggesting the possibility of a common ancestor for at least some of these chromosomes. The null frequencies showed concordance with the data published in Chang et al. [Higher failures of Amelogenin sex test in an Indian population group, J. Forensic Sci. 48 (2003) 1309-1313] on a smaller Malaysian population of 338 males which used a Y-STR triplex. In the current study, apart from the absence of the Amelogenin Y-locus, a complete absence of the DYS458 locus in all the nulls was also observed. This study together with the 2003 study has indicated a similar deletion region exists on the Y(p)11.2 band in all the 18 Y-chromosomes. Using bioinformatics, this deletion has been mapped to a region of at least 1.13 Mb on the Y(p)11.2 encompassing the Amelogenin, MSY1 minisatellite and DYS458 locus. Further, the Y-filer haplotypes revealed an additional null at Y-GATA H4 in two of the Indian males presented here.
Matched MeSH terms: Asian Continental Ancestry Group/genetics
Sinusitis is an important cause of morbidity and one of the major sources of income loss. Anatomical variations of the nose have been reported to predispose to sinusitis. These variations include concha bullosa, nasal septal deviation and oversized bulla. The aim of this study was to determine the proportion and the distribution of concha bullosa in patients with chronic sinusitis and to determine the relationship between concha bullosa and age, sex, ethnicity. A cross-sectional study was conducted at the Department of Ear, Nose and Throat in Kuala Lumpur Hospital (HKL). Data was collected retrospectively using a pretested proforma. All patients who underwent Sino nasal surgery between January 1999 and December 2000 and whose preoperative CT scans were available were included in the study. The CT scans were reviewed. Analysis was carried out using Statistical Package for Social Sciences. Out of 146 patients who underwent sinonasal surgery between January 1999 and December 2000, 101 (69.2% preoperative CT scans of these patients were available and these were reviewed. The proportion of patients with concha bullosa was 49.5%. The results showed that there was significant relationship between presence of concha bullosa and age and sex. The overall mean age of patient with concha bullosa was 35.7 years (95% CI 12.1-39.3) and ranged from 11-years to 56-years. The mean age of respondents with concha bullosa was significantly lower than patients without concha bullosa 41.98 (95% CI 37.6-46.3; t-test = 2.221; df=99; p < 0.05). Concha bullosa was significantly more in females (66.0%) compared to males (chi2 = 4.465, df=1, p < 0.05). There was no significant relationship between presence of concha bullosa and ethnicity.
Matched MeSH terms: Asian Continental Ancestry Group*
This study aimed to investigate the potential association of TYK2 and STAT3 genes with the susceptibility to Crohn's disease (CD) among Malaysians. DNA samples were obtained from 80 CD patients and 100 healthy controls. Polymerase chain reaction-restriction fragment length polymorphism methods were employed for genotyping, followed by statistical analysis. In our current study, none of the single nucleotide polymorphisms of either TYK2 or STAT3 was statistically associated with the susceptibility to CD in our local population (P > 0.05). In contrast, there was a statistically significant association between the G/G homozygotes of the STAT3 rs2293152 and the healthy control group (χ(2) = 6.229, P < 0.05). In conclusion, our study does not support the role of the TYK2 and STAT3 genes influencing CD susceptibility.
Matched MeSH terms: Asian Continental Ancestry Group/genetics*
Whole-genome sequencing across multiple samples in a population provides an unprecedented opportunity for comprehensively characterizing the polymorphic variants in the population. Although the 1000 Genomes Project (1KGP) has offered brief insights into the value of population-level sequencing, the low coverage has compromised the ability to confidently detect rare and low-frequency variants. In addition, the composition of populations in the 1KGP is not complete, despite the fact that the study design has been extended to more than 2,500 samples from more than 20 population groups. The Malays are one of the Austronesian groups predominantly present in Southeast Asia and Oceania, and the Singapore Sequencing Malay Project (SSMP) aims to perform deep whole-genome sequencing of 100 healthy Malays. By sequencing at a minimum of 30× coverage, we have illustrated the higher sensitivity at detecting low-frequency and rare variants and the ability to investigate the presence of hotspots of functional mutations. Compared to the low-pass sequencing in the 1KGP, the deeper coverage allows more functional variants to be identified for each person. A comparison of the fidelity of genotype imputation of Malays indicated that a population-specific reference panel, such as the SSMP, outperforms a cosmopolitan panel with larger number of individuals for common SNPs. For lower-frequency (<5%) markers, a larger number of individuals might have to be whole-genome sequenced so that the accuracy currently afforded by the 1KGP can be achieved. The SSMP data are expected to be the benchmark for evaluating the value of deep population-level sequencing versus low-pass sequencing, especially in populations that are poorly represented in population-genetics studies.
Matched MeSH terms: Asian Continental Ancestry Group/genetics*
Neuregulin-1 is widely investigated due to its hypothesised association with schizophrenia. Single-nucleotide polymorphisms rs764059, rs2954041 and rs3924999 were investigated (417 patients with schizophrenia and 429 controls). We failed to demonstrate a significant association between rs2954041 and rs3924999 with schizophrenia in the three ethnic groups studied (Malay, Chinese, and Indian), while rs764059 was found to be monomorphic.
Matched MeSH terms: Asian Continental Ancestry Group/genetics
This study was initiated to determine the psychometric properties of the Smart Phone Addiction Scale (SAS) by translating and validating this scale into the Malay language (SAS-M), which is the main language spoken in Malaysia. This study can distinguish smart phone and internet addiction among multi-ethnic Malaysian medical students. In addition, the reliability and validity of the SAS was also demonstrated.
Matched MeSH terms: Asian Continental Ancestry Group/psychology*
The Malay people are an important ethnic composition in Southeast Asia, but their genetic make-up and population structure remain poorly studied. Here we conducted a genome-wide study of four geographical Malay populations: Peninsular Malaysian Malay (PMM), Singaporean Malay (SGM), Indonesian Malay (IDM) and Sri Lankan Malay (SLM). All the four Malay populations showed substantial admixture with multiple ancestries. We identified four major ancestral components in Malay populations: Austronesian (17%-62%), Proto-Malay (15%-31%), East Asian (4%-16%) and South Asian (3%-34%). Approximately 34% of the genetic makeup of SLM is of South Asian ancestry, resulting in its distinct genetic pattern compared with the other three Malay populations. Besides, substantial differentiation was observed between the Malay populations from the north and the south, and between those from the west and the east. In summary, this study revealed that the genetic identity of the Malays comprises a mixed entity of multiple ancestries represented by Austronesian, Proto-Malay, East Asian and South Asian, with most of the admixture events estimated to have occurred 175 to 1,500 years ago, which in turn suggests that geographical isolation and independent admixture have significantly shaped the genetic architectures and the diversity of the Malay populations.
Matched MeSH terms: Asian Continental Ancestry Group/genetics*
BACKGROUND: This study examines the psychometric properties of the Malay version of the Montgomery-Ǻsberg Depression Rating Scale (MADRS-BM).
METHODS: A total of 150 participants with (n = 50) and without depression (n = 100) completed the self-rated version of the Montgomery-Ǻsberg Depression Rating Scale (MADRS-S), the Malay versions of the MADRS-BM, the Beck Depression Inventory-II (BDI-II-M), the General Health Questionnaire-12 (GHQ-12), and the Snaith-Hamilton Pleasure Scale (SHAPS-M).
RESULTS: With respect to dimensionality of the MADRS-BM, we obtained one factor solution. With respect to reliability, we found that internal consistency was satisfactory. The scale demonstrated excellent parallel form reliability. The one-week test-retest reliability was good. With respect to validity, positive correlations between the MADRS-BM, BDI-II-M, and the GHQ and negative correlation between the MADRS-BM and SHAPS-M provide initial evidence of MADRS-BM's concurrent validity. After adjusting for age, gender, ethnicity, educational level, and marital status, individuals with depression significantly reported higher MADRS-BM scores than did individuals without depression. Hence, there is additional evidence for concurrent validity of the MADRS-BM. Cut-off score of 4 distinguished individuals with depression from individuals without depression with a sensitivity of 78 % and a specificity of 86 %.
CONCLUSIONS: The MADRS-BM demonstrated promising psychometric properties in terms of dimensionality, reliability, and validity that generally justifies its use in routine clinical practice in Malaysia.
Matched MeSH terms: Asian Continental Ancestry Group/psychology