METHODS: Articles that report genetic polymorphisms, genotype frequencies and allele frequencies in CYP2C9, CYP2C19, CYP2D6 and CYP3A5 were retrieved from the PubMed database.
RESULTS AND DISCUSSIONS: A total of 86 studies that fulfilled the eligibility criteria representing different ethnic populations of SEEA, ie, Burmese, Chinese, Japanese, Karen ethnic minority, Korean, Malaysian, Philippino, Singaporean, Taiwanese, Thai, Indonesian, and Vietnamese, were included in the analysis. In general, the genotype frequencies across SEEA populations are comparable. The CYP2C9*1/*1 (69.3%-99.1%), *1/*3 (2.3%-20.1%) and *3/*3 (0%-2.2%) genotypes are reported in most SEEA populations. Six major CYP2C19 genotypes, ie, *1/*1 (6.25%-88.07%), *1/*2 (21.5%-86.46%), *1/*3 (0.8%-15.8%), *2/*2 (3.4%-14.5%), *2/*3 (0%-7.3%) and *3/*3 (0%-10.2%), are reported in most SEEA populations. Major CYP2D6 genotypes include *10/*10 (0%-69.6%), *1/*1 (0%-61.21%) and *1/*10 (0%-62.0%). Major CYP3A5 genotypes are *3/*3 (2.0%-71.4%), *1/*3 (16.0%-57.1%) and *1/*1 (0%-82.0%). Genotyping of abnormal genotypes of CYP2C9 (*1/*3), CYP2C19 (*1/*2, *1/*3), CYP3A5 (*1/*3) and CYP2D6 (*5/*10) associated with IM (Intermediate metabolizer) status, may be clinically beneficial in SEEA populations. Similarly, with CYP2C19 (*2/*2, *2/*3), CYP2D6 (*5/*5 ) linked to PM (Poor metabolizer), CYP2D6 (*10/*10, *1/*5 and to lesser extent *1/*4, *2/*5, *10/*41, *10/*49, *10/*14) and CYP3A5 (*1/*1) associated with EM (extensive metabolizer).
WHAT IS NEW AND CONCLUSION: Sufficient number of studies has provided comparable results in general. This review suggests that comparable genotype frequencies of CYP2C9, CYP2C19, CYP2D6 and CYP3A5 exist among the SEEA populations. It is noted that more research data are reported from East Asians compared with South-East Asians. Concerned efforts are required to establish partnerships among SEEA countries that will ensure sufficient data from South-East Asian countries which will assist in establishing the databases for SEEA populations.
METHODS: A systematic review and meta-analysis were performed of published studies from 1950 to 2010 using keyword searches in MEDLINE, EMBASE, EBM Reviews, and BIOSIS Previews.
RESULTS: In all, 477 abstracts were identified and data extracted from 93 studies, comprising 17,976 IBD patients and 27,350 age- and sex-matched controls. Major nucleotide oligomerization domain (NOD)-2 variants in Western Crohn's disease (CD) patients were not associated with CD in Han Chinese, Japanese, South Korean, Indian, and Malaysian populations. New NOD2 mutations were, however, associated with CD in Malaysians (JW1), Han Chinese, and Indians (P268S). Autophagy-related protein 16-linked 1 (ATG16L1) was not associated with CD in East Asians (odds ratio [OR] 0.97; 95% confidence interval [CI] 0.84-1.13). Interleukin (IL)-23R was associated with CD in South Koreans (OR 1.8; 95% CI 1.16-2.82) and a single nucleotide polymorphism in IL-23R (Gly149Arg) was protective of CD in Han Chinese (OR 0.3; 95% CI 0.15-0.60). Tumor necrosis factor (TNF) superfamily gene-15 (SF15) polymorphisms were associated with CD (OR 2.68; 95% CI 1.86-3.86), while TNF-308 polymorphisms (OR 1.82; 95% CI 1.15-2.9), cytotoxic T lymphocyte antigen (CTLA)-4 (OR 2.75; 95% CI 1.22-6.22) and MICA allele (OR 2.41; 95% CI 1.89-3.07) were associated with ulcerative colitis in Asians.
CONCLUSIONS: Genetic mutations of IBD in Asians differ from Caucasians. New mutations and susceptibility genes identified in Asian IBD patients provide an opportunity to explore new disease-associated mechanisms in this population of rising incidence.
METHODS: Articles published in PubMed, MEDLINE, CINAHL and Science Direct from 2005 to 2015 were searched systematically. Studies were included if constipation satisfied the Rome II and or III criteria. Study populations consisted of Asian adults above 18 years old and with sample size above 50.
RESULTS: Of 2812 articles screened, 11 met the eligibility criteria. Constipation among Asian adults was characterized by three core symptoms of 'straining' at 82.8%, 'lumpy and hard stool' at 74.2% and 'sensation of incomplete evacuation' at 68.1% and the least frequent symptom was 'manual maneuver to facilitate defecation' at 23.3%. There was heterogeneity in frequency patterns of core symptoms between different Asian studies but also differences in core symptoms between constipation subtypes of functional constipation and irritable bowel syndrome with constipation.
CONCLUSIONS: In general, Asian adults perceive constipation symptoms in a similar but not equivalent manner to the West. Recognition of core symptoms will increase the diagnostic confidence of constipation and its subtypes but more studies of the various specific Asian populations are needed to address their differences.