23andme celiac disease genetic testing involves assessment of genetic markers associated with gluten sensitivity and celiac disease from your 23andme raw data. The DNA raw data is available to you when you buy the 23andme genetic test for Ancestry.
In recent years, the number of people found to have celiac disease has grown many folds due to increased awareness and ease of diagnosis.
So, why do you need to do genetic testing for coeliac disease? About 1 in 100 people in the U.S have celiac disease. However, 2.5 million people with celiac disease do not know that they have it, i.e they are undiagnosed.
Here are a few important facts about celiac disease genetic testing that everyone must know.
- 23andme celiac disease testing indicates your risk for celiac disease: The 23andme celiac disease report interprets 2 genetic haplotypes called HLA-DQ2.5 and HLA-DQ8 HLA-DQ2.5- rs2187668 and HLA-DQ8 -rs7454108. A haplotype refers to a group of genes that are inherited together from one parent. Research studies have shown that people who carry either one or both these two haplotypes constitute 95 percent of all celiac disease incidences.
- What does celiac disease mean?: Celiac (or coeliac) disease is an autoimmune condition that occurs in people with a genetic predisposition. In such individuals, gluten, present in wheat, affects the villi in the small intestines. Gluten is a glue-like protein which is also found in rye, barley and spelt.
- Is celiac disease hereditary? Celiac disease is hereditary. Individuals with a first degree relative of someone with celiac disease has a one in 10 chance of developing celiac disease.
- Is celiac disease genetic? Since it is hereditary, it is genetic too. To develop celiac disease, HLA-DQA1 and HLA-DQB1 risk alleles are required but they may not be sufficient for the development of the disease. The HLA-DQ heterodimers, which are encoded by these HLA-DQ alleles, present wheat peptides to CD4+ T cells. This activates the T cells and, thereby, activating an inflammatory immune response in the intestine.
- What are the symptoms of celiac disease? There are more than 200 symptoms identified for this condition. Among children, celiac disease is associated with diarrhoea, vomiting, short stature, irritability, weight loss or abdominal bloating. Celiac symptoms in adults are more to do with autoimmune condition than about abdominal discomfort. Only one-third of celiac disease adult patients experience diarrhoea, other symptoms include osteoporosis, arthritis, depression, missed menstrual period, canker sores or unexplained anaemia.
- What is the difference between celiac disease and gluten sensitivity?
| Celiac Disease | Gluten Intolerance |
|---|---|
| Rare condition. Only 1% of the population is known to be affected with this condition. |
Compared to celiac disease, gluten intolerance is more prevalent. |
| This is an autoimmune condition and it involves the immune system. | This is not an autoimmune condition and it does not involve the immune system. Symptoms of gluten intolerance or gluten sensitivity are restricted to abdominal discomfort |
| The only treatment is to completely avoid gluten in the diet | The amount of gluten consumed should be below the body's threshold level. |
| This is a more severe condition | This is less severe when compared with celiac disease |
- Genetic testing for celiac disease: HLA DQ testing for gluten sensitivity helps in identifying the presence of genetic variants which have been shown to be associated with an increased risk. However, only 3% of individuals with these genetic variants have been found to develop this condition. Those with high-risk variants should watch out for symptoms or use this test in conjunction with a blood test or an upper endoscopy biopsy. Individuals who do not carry any risk variant will not develop the condition.
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How to interpret 23andme celiac disease results: 23andme celiac disease report focuses on two haplotypes. A considerable percentage of celiac disease incidence is caused due to these two variants.Find your variant in the 23andme raw data- HLA DQ 2.5 (rs2187668)
Genotype
HLA DQ 2.5 (rs2187668)Phenotype CC [Advantage] More likely to be gluten tolerant CT Moderate risk for gluten intolerance TT [Limitation] More likely to be gluten intolerant
Find your variant in the 23andme raw data- HLA DQ 8 (rs7454108)
Genotype Phenotype AA [Advantage] More likely to be gluten tolerant AG Moderate risk for gluten intolerance GG [Limitation] More likely to be gluten intolerant
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What is the 23andme celiac disease report missing out?23andme celiac report interprets only HLA DQ2.5 and HLA DQ8, it does not provide the results for HLA DQ 2.2 and HLA DQ 7. The Xcode.Life health report coves more gene variants and SNPs associated with celiac disease and gluten sensitivity than the 23andme celiac report. Besides 23andme raw data, Ancestry DNA raw data, FTDNA raw data and raw data from other companies can also be uploaded.Find your variant in the 23andme raw data- HLA DQ 2.2 (rs2395182, rs7775228,rs4713586)
Find your variant in the 23andme raw data- HLA DQ 8 (rs7454108)Genotype Phenotype rs2395182- T [Limitation] More likely to be gluten intolerant rs7775228- G [Limitation] More likely to be gluten intolerant rs4713586-A [Limitation] More likely to be gluten intolerant
Genotype Phenotype GG [Advantage] More likely to be gluten tolerant AG Moderate risk for gluten intolerance AA [Limitation] More likely to be gluten intolerant -
What are some of the research studies for celiac disease and HLA DQ gene testing? In a study conducted on 4,918 celiac disease patients and 5,684 controls of European ancestry, the HLA DQ genes under study were found to have a significant association with the risk for celiac disease.
In another study conducted on 754 patients, it was found that DQ2.2, DQ2.5, DQ2.7, and DQ8 could be used to predict >95% of celiac disease patients. This study signifies the importance of testing for all these 6 polymorphisms in order to determine risk. Therefore, 23andme celiac disease report may not be sufficient.To view or order your nutrition report with Xcode, click here.
References:
Thank you for the great article. Will gluten sensitivity eventually lead to celiac over a period of time?
Hi shane. I am glad you liked the article.
There isn't sufficient research available to know how many people who are gluten sensitive develop celiac disease. What is known, according to a research study, is that 13% of people with celiac disease have relatives who develop gluten sensitivity.
Here are a couple of references you may find useful
https://www.webmd.com/digestive-disorders/news/20131212/celiac-disease-gluten-sensitive#1
https://www.clinicalnutritionjournal.com/article/S0261-5614(14)00218-0/fulltext