PERSPECTIVES ON ANCESTRAL LINEAGES AND GENETIC MARKERS OF MALAY POPULATION IN PENINSULAR MALAYSIA (Perspektif Keturunan Dan Penanda Genetik Populasi Melayu Di Semenanjung Malaysia) / Jurnal Sains Kesihatan Malaysia

@#The Malay people are the majority in Peninsular Malaysia, but their population structure and genetic profile remain poorly studied. The exposure to the origins of Malays and their sub-ethnic groups is vital prior to study about their genetic profiles as it can narrow down the haplogroups of their ancestral lineages. In this review, we have highlighted theories related to the origin of Malays from Yunnan, New Guinea, Taiwan, Sundaland, Nusantara and the theory of Bani Jawi. Nevertheless, these theories were established based on speculations without evidence. Despite the theories developed, the migration of Malay population is more prominent during the era of Malacca Sultanate. The trading activities and seafaring way of life had welcomed various ethnic groups in Peninsular Malaysia which formed a part of the Malay population today. Thus, the origin of major sub-ethnic groups of Malay population are discussed in this paper. The origin of Malay community has a key relationship with modern genomic field that was conducted through mitochondrial DNA analysis. Human identification in forensic application is tedious due to the need for sequencing whole DNA profile of Malay population. Therefore, identification of specific genetic markers for Malay population is vital to facilitate forensic investigation. We gathered data by systematically searched with Google Scholar, Pubmed, Science Direct with advanced search builder for papers titles with Malay population and genetic markers. This study shed some light on the mitochondrial DNA markers of indigenous people and Malay population in Peninsular Malaysia which can be used in future prospects.

Allelic Diversity of the Hemochromatosis Gene (HFE) in Malays, Chinese and Indians

@#Introduction: Hereditary hemochromatosis (HH) is an autosomal recessive disorder that causes accumulation of iron in circulating blood and organs. The disease is associated with H63D, S65C and C282Y variants of the haemochromatosis (HFE) gene and, if not treated can cause organ damage and may prove fatal. The main objectives of the present survey were to screen these genetic variants and establish risk profiles for developing HH in Malays, Chinese and Indians. Methods: A total of two hundred and twenty-two unrelated and healthy individuals together representing Malay, Chinese and Indian ethnicities in Malaysia were scored for the H63D, S65C and C282Y variants using a polymerase chain reaction-restriction fragment length polymorphism technique. Results: There are clear differences in H63D, S65C and C282Y allele and genotype frequency distributions between Malays, Chinese and Indians. In particular, H63D is more common in Chinese (5.19%) and Indians (7.29%), while S65C is more common in Malays (1.03%) and Chinese (1.04%). In addition, a susceptibility genotype for HH (the compound heterozygote for C282Y and H63D) was only detected in Indians (0.02%). Conclusion: Overall, our study is the first to provide data on the prevalence of H63D, S65C, and C282Y genetic variants and HH risk profiles for Malays, Chinese and Indians.

Corneal thickness and morphology after orthokeratology of six-month lens wear among young Malay adults

@#Background: Menicon Z night orthokeratology (OK) lenses was introduced in Malaysia in 2015 and to date there is no report on its effects on the cornea. The objective of this study was to examine short term changes in corneal thickness and morphology of endothelial cells in young Malay adults after wearing Menicon Z night OK lenses. Methods: Corneal thickness was measured at the central and mid-peripheral locations of 20 participants aged 22.45±1.19 years using Tomey SP-3000 A-scan ultrasonography. Endothelial images of the central and peripheral locations captured using Tomey EM-3000 specular microscope were noted. Corneal thickness, endothelial cell density (ECD), coefficient of variation in cell size (CV), and hexagonality (HEX) at baseline, 24 hours, three months and six months after treatment were noted and analysed using repeated measure analysis of variance. Results: Central corneal thickness decreased significantly over a three-month period (p=0.001) and stabilised thereafter. There were no significant changes in thickness in all peripheral areas measured (p>0.05), and in ECD, CV and HEX after the six-month period (p>0.05). Conclusions: The current study showed that significant thinning of central cornea and none at the mid-periphery. OK lens wear with Menicon Z night lenses had no effects on corneal morphology over the six month period.

von Willebrand Factor Profiles of the Different ABO Blood Groups Among the Malay Population

@#The National Blood Center, Kuala Lumpur interprets laboratory results for the von Willebrand factor (VWF) profile based on guidelines which were established based on the Caucasian population. The VWF profiles among the Malay population has not yet been established. The current study aims to determine the VWF profiles of the different ABO blood types among Malays and to evaluate their association with demographic characteristics and smoking habits. Methods: One hundred and forty Malay donors were involved. Factor VIII (FVIII:C), VWF antigen (VWF:Ag), and ristocetin cofactor (VWF:RiCof) levels and collagen binding activity (VWF:CBA) were measured by coagulometric clot detection, latex agglutination, and enzyme-linked immunosorbent assay. Results: The majority of donors (59.3%) were 30–49 years old, male (81.43%), non-smokers (74.3%), and overweight (71.4%). The Malay VWF:Ag were slightly higher than those of Caucasians, Indians, Thais, and Chinese, but the average ratios of VWF activity (i.e., VWF:RiCof level and VWF:CBA) to VWF:Ag were slightly lower than those of the other populations. The highest level of VWF:Ag was found among those with the B blood group, followed by types A and O. Conclusion: Malays with type O blood had lower values of the components of the VWF profile compared to subjects with non-O blood. The higher levels of these elements and lower VWF activity to VWF:Ag ratio in Malays compared to other populations suggest that ethnicity impacts the plasma VWF levels and their interaction with collagen and platelets.

Ethnic disparity in inter-arm systolic blood pressure difference and its determinants among Asians with type 2 diabetes: A cross-sectional study / Journal of the ASEAN Federation of Endocrine Societies

@#<p><strong>OBJECTIVES:</strong> An inter-arm difference in systolic blood pressure (IADSBP) of 10 mmHg or more has been associated with cardiovascular disease (CVD) and increased mortality in T2DM patients. We aim to study ethnic disparity in IADSBP and its determinants in a multi-ethnic T2DM Asian cohort.<br /><strong>METHODOLOGY:</strong> Bilateral blood pressures were collected sequentially in Chinese (n=654), Malays (n=266) and Indians (n=313). IADSBP was analyzed as categories (<br /><strong>RESULTS:</strong> Malays (27.4%) and Indians (22.4%) had higher prevalence of IADSBP ?10 mmHg than Chinese (17.4%) (p=0.002). After adjustment for age, gender, duration of diabetes, hemoglobin A1c, body mass index (BMI), heart rate, pulse wave velocity (PWV), estimated glomerular filtration rate (eGFR), albumin-to-creatinine ratio (ACR), smoking, hypertension, soluble receptor for advanced glycation end products (sRAGE), and usage of hypertension medications, ethnicity remained associated with IADSBP. While Malays were more likely to have IADSBP ?10 mmHg than Chinese (OR=1.648, 95%CI: 1.138-2.400, p=0.009), Indians had comparable odds with the Chinese. BMI (OR=1.054, 95%CI: 1.022-1.087, p=0.001) and hypertension (OR=2.529, 95%CI: 1.811-3.533, p<0.001) were also associated with IADSBP ?10 mmHg.<br /><strong>CONCLUSION:</strong> IADSBP in Malays were more likely to be ?10 mmHg than the Chinese which may explain their higher risk for CVD and mortality. Measuring bilateral blood pressures may identify high-risk T2DM individuals for intensive risk factor-management.</p>

Concurrent Inheritance of Deletional α-thalassaemia in Malays with HbE Trait

Introduction: HbE is the commonest beta haemoglovin (Hb) variant in Southeast Asia. It causes a reduction in synthesis of beta-globin E (βE) chain. Studies indicate HbE coinherited with α-thalassaemia leads to a milder clinical phenotype. This study investigates the concomitant inheritance of α-thalassaemia in Malays with HbE. Methods: Four hundred and fourteen (414) blood samples were screened for haemoglobinopathy using primarily the first 3 steps of the BHES [(B) blood counts, blood film: (H), HPLC; (E),elstrophoresis; (S),stability)] protocol. Complete blood counts were generated on an automated blood cell analyser, HB typing with cation exchange high-performance liquid chromatography (HPLC) and Hb typing with cation exchange high-performance liquid chromatography (HPLC) and Hb electrophoresis at an alkaline pH (pH 8.5). Forty-five (10.9%) were identified as HbE trait and DNA analysis was done for deletional α-thalassaemia using a single-tube multiplex-PCR assay. Results: Among the 45 subjects with HbE trait. 4 (8.9%) were found to have alpha-thalassaemia-2 (α⁺) (α-3.7 kb deletion) and 1 (2.2%) the alpha-thalassaemia-1 (α⁰) (—SEA 20.5kb deletion) defects respectively. Discussion: These findings show that 11.1% of Malays with HbE inherit alpha-thalassaemia concurrently. The most prevalent interaction found was a double heterozygote for HbE/α-thalassaemia 2, followed by HbE/α-thalassaemia 1. Conclusion: Molecular screening of deletional α-thalassaemia identified its concurrent inheritance in 11.1% of Malays who were HbE carriers. This information will guide genetic counseling and the planning of treatment modalities in patients with HbE alpha-thalassaemia.

The timing and sequence of emergence of permanent teeth in Malay schoolchildren in Kota Bharu, Malaysia

The purpose of this study was to determine the timing and sequence of emergence of the first 28 permanent teeth in a cross-section of Malay children in the district of Kota Bharu, in northeastern Peninsula Malaysia. The sample consists of 478 boys and 908 girls of Malay descent aged between 5-19 years. The criterion for tooth emergence was the appearance of the tooth through the gingivae. Descriptive statistics were calculated and probit regression analysis performed to determine the mean age of emergence of the permanent dentition. The mean age at emergence was found to conform to general trends, with emergence seen earlier in girls than in boys. Comparisons were made with the Chinese (Hong Kong) and the Punjabi (Chandigarh) profiles, which showed earlier emergence timings in those ethnic groups. The emergence timing in Malays, however, was earlier than in Thais (Central Thailand). The sequence of emergence was determined by referring to the mean age of tooth emergence of individual teeth and conforms to the general trend seen in other studies.