Search the Community
Showing results for tags 'variation'.
Found 2 results
Celiac.com 09/16/2013 - Until recently, researchers thought celiac disease was mainly a problem in Northern Europe and Australasia, and uncommon in North America and the Middle East. However, with better data, researchers now regard celiac disease to be equally common in all these places. Celiac disease is still generally seen as rare in Asia and Sub-Saharan Africa, but a team of researchers wanted to get a better idea of geographical differences and time trends in the frequency of celiac disease. The research team included J. Y. Kang, A. H. Y. Kang, A. Green, K. A. Gwee, and K.Y. Ho. They are affiliated with the Department of Gastroenterology, St George's Hospital, London, UK, the Yong Loo Lin School of Medicine at the National University of Singapore, and with the Department of Gastroenterology and Hepatology at the National University Health System in Singapore. To get the data that would help them to compare geographical differences and time trends, the team conducted Medline and Embase searches covering a period from 1946 to 1980, using the key words: coeliac disease or celiac disease + prevalence, incidence or frequency. Their data showed significant differences between and within countries in the prevalence and incidence of celiac disease. For example, in all of reported English medical literature, there have been only 24 ethnic Chinese and Japanese patients with celiac disease. Of celiac-associated HLA DQ antigens, DQ2 occurs in 5–10% of Chinese and sub-Saharan Africans, compared to 5–20% in Western Europe. DQ8 occurs in 5–10% of English, Tunisians and Iranians, but in less than 5% of Eastern Europeans, Americans and Asians. Rates and overall numbers of both clinically and serologically diagnosed celiac disease have risen in recent years. Celiac disease is increasing in frequency, with significant geographical differences. The team's geographical and temporal differences seem genuine, but a large number of hypothesis and lack of diagnostic facilities have made it difficult to reach any solid conclusions. Although few cases have been found in Asia and Sub-Saharan Africa, there is a significant prevalence of HLA DQ2 and wheat consumption is about the same as in Western Europe. It is possible that celiac disease may become more common in these countries in the future. Source: Aliment Pharmacol Ther. 2013;38(3):226-245.
Celiac.com 08/20/2009 - For the first time, a team of celiac disease researchers has discovered a role for the main inherited celiac-associated genetic variation, connecting altered NF-kB signalling with risk variants associated with Celiac disease in TNFAIP3 and REL. The research team was made up of G. Trynka, A. Zhernakova, J. Romanos, L. Franke, K. A. Hunt, G. Turner, M. Bruinenberg, G. A. Heap, M. Platteel,1 A. W. Ryan, C. de Kovel, G. K. T. Holmes, P. D. Howdle, J. R. F. Walters, D. S. Sanders, C. J. J. Mulder, M. L. Mearin, W. H. M. Verbeek, V. Trimble, F. M. Stevens, D. Kelleher, D. Barisani, M. T. Bardella, R. McManus, D. A. van Heel, C. Wijmenga. An earlier celiac disease genome-wide association study (GWAS) identified risk variants in the human leucocyte antigen (HLA) region and eight new risk areas. To find more celiac disease locations, the research team chose to examine 458 single nucleotide polymorphisms (SNPs) that exhibited weaker ties in the GWAS for genotyping and analysis in four independent cohorts. The 458 SNPs were found among 1682 cases and 3258 controls from UK, Irish and Dutch populations. The team combined the results with the original GWAS cohort involving 767 UK cases and 1422 controls), in which six SNPs showed association with p,1610. Those six were then genotyped in an independent Italian celiac cohort (538 cases and 593 controls). The research team found two new celiac disease risk regions: 6q23.3 (OLIG3-TNFAIP3) and 2p16.1 (REL). In the final combined analysis of all 2987 cases and 5273 controls, both regions achieved genome-wide significance (rs2327832 p=1.3610, and rs842647 p=5.2610). The researchers used RNA isolated from biopsies and from whole blood RNA to look at gene expression. They observed no changes in either gene expression, or in the correlation of genotype with gene expression. From these results, the research team concluded that both TNFAIP3 (A20, at the protein level) and REL are key mediators in the nuclear factor kappa B (NF-kB) inflammatory signalling pathway. For the first time, researchers have identified a role for main inherited variation in this important biological pathway that predisposes individuals to celiac disease. Currently, the HLA risk factors and the 10 established non-HLA risk factors provide an explanation for about 40% of inheritance factors for celiac disease. Clearly, more research is needed to isolate the other 60% of inheritability factors for celiac disease. Success in this very important area promises to open up the understanding of celiac disease, and to help speed new treatments, and possibly a cure. Gut 2009;58:1078–1083.