Celiac disease, also known as gluten intolerance, is an autoimmune disorder of genetically predisposed individuals, provoked by gluten proteins in wheat and related foods. Wikipedia
SNPs associated with celiac disease:
- HLA-DQ
- rs2187668 (HLA-DQA1)
- In a 2003 survey of European studies, more than 85% of celiac patients carry the same HLA-DQ heterodimer DQA1*05 DQB1*02 (aka DQ2.5) encoded in cis or in trans [PMID 12209133]; almost all the remaining cases carry either the DQA1*05 or the DQB1*02 part of the DQ heterodimer, or DRB1*04-DQ8. [PMID 14571266]
- rs2187668(A) is a tag SNP for DQ2.5 [PMID 18509540]
- rs2395182, rs7775228, and rs4713586 create a haplotype tag for DQ2.2; see gs221 [PMID 18509540]
- rs7454108 tags the HLA-DQ8 haplotype
- A large study of 2,000+ celiac disease patients found SNP associations in 7 chromosomal regions. Six of these regions harbor genes controlling immune responses, including CCR3, IL12A, IL18RAP, RGS1, SH2B3 (rs3184504), and TAGAP. [PMID 18311140]
- near CCR3
- rs6441961 (risk allele T) [PMID 19542083] [PMID 19648290]
- IL18RAP
- rs917997 (possibly a weak association) [PMID 19542083]
- near the IL21 gene
- rs13119723 (risk allele G) [PMID 17558408] [PMID 18418394]
- rs6822844 (higher risk allele is G, since T allele is reported to reduce risk) [PMID 17558408] [PMID 18418394]
- near the LPP gene
- near ITGA4 [PMID 19648293]
Although the HLA-DQ2 and DQ8 haplotypes are associated with gluten intolerance, as a 2010 blog post indicates, the frequency of these haplotypes (20-30%) is much higher than the frequency of celiac disease (~1%), so perhaps the primary value of SNP testing in this context is to rule out the likelihood of gluten intolerance. In other words, if you are among the 70-80% of individuals who do not carry HLA-DQ2 and/or DQ8 haplotypes, you are quite likely (> 95%) to tolerate gluten and to not be at risk for celiac disease.
