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).

MATERIALS AND METHODS: This collaborative research between the National Space Agency (ANGKASA), Universiti Teknologi MARA, Malaysia and Institute of Biomedical Problems (IBMP), Russia was conducted at the Russian Academy of Sciences IBMP, Moscow, Russia. Six multi-national cosmonauts were assigned to live in a ground-based confined module for 520 days. Standard exercise and diet regime were instituted throughout the isolation phase. Six age, ethnic and gender-matched healthy, free-living ground controls were recruited in parallel. Serial serum and whole blood were analysed for biomarkers of prothrombogenesis [plasminogen activator inhibitor-1 (PAI-1) and homocysteine] and oxidative stress [oxidised low-density lipoprotein (ox-LDL) and malondialdehyde (MDA)].

RESULTS: There were significantly lower concentrations of PAI-1 and homocysteine in cosmonauts during confinement compared to the controls. There were no significant differences seen in the concentrations of biomarkers of oxidative stress during confinement but there was a significant percentage change increment for serum MDA in cosmonauts.

METHODS: Surveys were conducted in five Negrito settlements in Kelantan and Perak states in Malaysia. A total of 150 participants were recruited. Clinical history was taken and physical examination was performed. Five millilitres of whole blood were collected and tested for hepatitis B surface antigen (HBsAg) using electrochemiluminescence immunoassay.

RESULTS: Participants were mainly from the Bateq (49.3%) and Mendriq (29.4%) sub-tribes. Overall, 13 subjects (8.7 %); nine males and four females were HBsAg positive. Nine of the HBsAg positive subjects were ≥35 years old. All of them had history of home deliver without evidence of antenatal record. Six (46%) of the HBsAg positive subjects had tattoo and body piercing in the past.

METHODS: Genomic DNAs were extracted from the blood samples followed by whole-genome sequencing. The reads were aligned to the reference human genome hg19 and variants in the CYP2D6 gene were analyzed. CYP2D6*5 and duplication of CYP2D6 were analyzed using previously established methods.

RESULTS: A total of 72 single nucleotide polymorphisms were identified. CYP2D6*1, *2, *4, *5, *10,*41, and duplication of the gene were found in the Orang Asli, whereby CYP2D6*2 and *41 alleles are reported for the first time in the Malaysian population.