METHODS: A large-scale prospective seroepidemiological study in West and East Malaysia using the HEL-p II commercial enzyme-linked immunosorbent assay kit (AMRAD, Melbourne, Australia) to detect H. pylori antibodies. Populations surveyed in West Malaysia were a rural community from Kuala Pilah, and blood donors from Kuala Lumpur and Kota Baru. Subjects studied in East Malaysia were volunteer blood donors from Kota Kinabalu, and blood donors and healthy volunteers from Sibu. Statistical analyses using multiple logistic regression analysis were carried out to identify independent risk factors for H. pylori infection
RESULTS: A total of 2,381 subjects were evaluated. H. pylori prevalence varied from different areas of study and ranged from a low of 26.4% in blood donors from Kota Baru to a high of 55.0% in Kota Kinabalu. The most striking differences, however, were noted in the prevalence rates among different racial groups. Prevalence rates among the Malays ranged from 11.9 to 29.2%, while the Chinese ranged from 26.7 to 57.5%, and those of Indians in two studies were 49.4 and 52.3%. In every location, Malays had a significantly lower prevalence compared with the other races. The highest prevalence rates were recorded among the indigenous races in Kota Kinabalu, East Malaysia. There was no difference between males and females in the studies. An increasing trend with age was noted in the majority of studies; however, no increase in prevalence rates was noted among the Malays.
CONCLUSIONS: The pattern of infection in a multiracial population in Malaysia points to a 'racial cohort' phenomenon. The infection appears to be confined to a racial group, with the Malays having consistently low prevalence rates. This observation may provide clues to the mode of transmission of infection.
RESULT: By combining SNP information from literatures, GWAS study and NCBI ClinVar, 18 unique SNPs were selected for further analysis. From these 18 SNPs, 10 SNPs came from previous study of Helicobacter pylori infection among Malay patients, 6 SNPs were from NCBI ClinVar and 2 SNPs from GWAS studies. The analysis reveals that both Royal Kelantan Malay genomes shared all the 10 SNPs identified by Maran (Single Nucleotide Polymorphims (SNPs) genotypic profiling of Malay patients with and without Helicobacter pylori infection in Kelantan, 2011) and one SNP from GWAS study. In addition, the analysis also reveals that both Royal Kelantan Malay genomes shared 3 SNP markers; HBG1 (rs1061234), HBB (rs1609812) and BCL11A (rs766432) where all three markers were associated with beta-thalassemia.
CONCLUSIONS: Our findings suggest that the Royal Kelantan Malays carry the SNPs which are associated with protection to Helicobacter pylori infection. In addition they also carry SNPs which are associated with beta-thalassemia. These findings are in line with the findings by other researchers who conducted studies on thalassemia and Helicobacter pylori infection in the non-royal Malay population.