<<Disclaimer: Verify this information before applying it to your situation.>> Dear list, I am receiving few emails asking me for references about dependability of genetic testing. I found web site, where you can confirm it or perhaps challenge with authors. It seems to me that only strict gluten free diet is reliable to find out if the health condition improves. But with CD most at the time are associated bacteria overgrowing in intestine. That means patient could feel better after short time, but get worse again, because of bacteria (Candida Albicans). Most people when start GF diet trying to replace gluten with GF cookies, which contain lots of sugar what bacteria only need to thrive. In some cases people give up GF lifestyle and go back to regular diet and say “Gluten free diet didn’t make me feel better”. I agree with all of you that it is tough to get over with CD. But it is worth all the effort in the long term. Kevin ----------------------------------------------------------------------------------------------------------------------------------------- http://www.enabling.org/ia/celiac/cel-hla.html#Q6 Questions and answers on HLA typing and Celiac Disease Copyright by Michael Jones, Bill Elkus, Jim Lyles, and Lisa Lewis 1995, 1996 - All rights reserved worldwide. Disclaimer Thxis file is a summary of various posts made on the CELIAC List about genetics and celiac, and more specifically about HLA typing in Celiac Disease. It has been supplemented by private E-Mail with various experts in this area of CD, and has been reviewed for technical accuracy by Drs. Ludvig Sollid (University of Oslo) and Karoly Horvath (University of Maryland), two of the CEL-PRO experts. This file is formatted as a question and answer session. Which HLA markers are associated with Celiac Disease? I have been confused, sometimes reading about DQ2, at other times about DR3, B8 and other markers. The three markers DR3, B8 and DQ2 are all associated with Celiac Disease. The reason for this is that the genes which code for B8, DR3 (also termed DRw17) and DQ2 are in linkage disequilibrium. They are part of a gene segment that is usually maintained as a gene block. This fact has posed a problem in the work to identify which molecules are actually involved in the development of Celiac Disease and which alleles are just associated with CD because the genes coding for these molecules are us ually linked with the predisposing genes. In other words: Which of B8, DR3 or DQ2 are actually involved in the development of Celiac Disease and which are just marker molecules? Those Celiacs who are not DR3 positive very often are DR5/DR7 (DR5 is coded for by genes on the one chromosome and DR7 is coded for by genes on the other chromosome). Individuals who are DR3, almost always also are DQ2 (because the genes coding for DR3 and DQ2 are in linkage disequilibrium - they are in a conserved gene block). The names of the genes in this gene block that jointly code for DQ2 are DQA1*0501 (which codes for the alpha chain) and DQB1*02 (which codes for the beta chain). The DQA1*0501 gene also exists in a gene block that contains the gene coding for DR5, and the DQB1*02 gene exists in a gene block that contains the gene coding for DR7. Individuals who are DR5/DR7 may thus also possess the DQA1*0501 and DQB1*02 genes. In contrast to individuals who are DR3-DQ2 the DQ genes in DR5/DR7 individuals which code for DQ2 are located on two different chromosomes. This explains why DR5/DR7 individuals also have a predisposition to develop Celiac Disease and strongly indicates that it is DQ2 coded for by the DQA1*0501 and DQB1*02 genes that actually are involved in the development of Celiac Disease. About 95% of the Celiac population carry these particular genes. In addition, another 4-5% of the Celiac population have genes that code for DR4 and DQ8 molecules (the genes coding for DR4 and DQ8 are maintained in block of genes). Probably it is the DQ8 molecule that mediates the disease predisposition in this subgroup of patients. Some very few Celiacs are neither DQ2 nor DQ8 implying that HLA typing is not a perfect predictor of risk for Celiac Disease. http://www.enabling.org/ia/celiac/cel-hla.html#Q6 * Please include your location in all posts about products *