The genetic test for lactose intolerance

Ok, I have been showing the symptoms of lactose intolerance for months (or years) and maybe I have already taken the Breath Test , it's time to check my condition through the Genetic Test for lactose intolerance .

The test is simple, it is done via a buccal swab (sterile cotton bud in the mouth) or blood sampling. The cost is higher than the Breath Test but, unlike the latter, it does not give physiological problems in case of positivity . The result will be delivered to you after a few days.

Attention : the genetic test does not provide the same information as the H2 Breath Test but it informs us about a possible predisposition of the organism to become intolerant (we can already be intolerant for some time, we can become one now or we could become one in years). The tests are therefore complementary rather than alternative and we still recommend carrying out a Breath Test for lactose intolerance, which also indicates how much we are intolerant to the substance TODAY.

Why a GENES test?

All our cells have a limited life and must reproduce in order to keep the body functioning, that is, alive. To pass on the characteristics of the individual - character - there must be a passage of information between the cells , to "train" the new ones to perform the required jobs.

How is this information transmitted? I don't want to go into too much detail but I like to explain all the points, leaving the reader to choose the jump of the following paragraph.

Cellular organisms use messenger RNA (mRNA) to transmit the aforementioned genetic information (using the letters G, U, A, and C to indicate guanine, uracil, adenine and cytosine) which direct the synthesis of specific proteins. Enzymes are specialized proteins for catalytic function that control all metabolic events in the body. Lactose is broken down in the intestine into glucose and galactose by an enzyme: the lactase enzyme. This enzyme is encoded by the “LPH” GENE mapped on chromosome 2 of our DNA. At birth, lactase levels are very high but decline after weaning. From two years of age, there is a gradual decrease in lactase mRNA transcripts, associated with a reduction in enzymatic activity .

Over time, therefore, we lose the "education" to create the enzyme lactase , responsible for the proper digestion of lactose.

The test described here allows us to verify whether this instruction, this message, is still present within our DNA or not .

Another heavy paragraph:

Specifically, lactose intolerance in adulthood, also called hypolactasia, is due to a variation (polymorphism) of the genotype associated with the LPH gene. The variant C in homozygosity (genotype C / C), associated with a lower transcription of the gene, correlates with the lactose intolerance phenotype. About 60% of people have this anomaly. The genetic test for lactose intolerance allows to discriminate who has both healthy copies of the gene (T / T), who has only one healthy (T / C) and who has both mutated (C / C).

The subject who presents both mutated copies (C / C, POSITIVE TEST ) is predisposed to lactose intolerance and, if already suffering from the typical symptoms of intolerance, the test is the confirmation of the fact that he is no longer able to create the enzyme lactase ( primary deficiency ).

The genetic result is certain and the subject will not be able, in the future, to have stocks of the enzyme capable of dissolving, and therefore digesting, lactose - unless administered from the outside, see the lactase enzyme tablets -.

I emphasize, however, that in order to be defined as lactose intolerant, the typical symptoms of intolerance must be perennial, that is, not due to other diseases of the digestive system.

In case of different and temporary problems , the positive genetic test informs us that we will become intolerant but our annoyances today may not be correlated with the lactase enzyme deficiency .

Instead, in the case of lactose mal-digestion but of a genetic test for NEGATIVE intolerance, we will have the confirmation that our intolerance will have a different, transitory and recoverable character .

It will have a secondary induced form (secondary deficit ) as a consequence of other pathologies such as, for example, damage of the intestinal mucosa following antibiotic treatments, gastroenteritis, alcoholism, celiac disease, nutritional disorders, infections of the digestive and intestinal tract, surgery or other drug therapies. In this case, the solution to the symptomatology will be sought with specific insights, through tests that a good gastroenterologist will be able to advise you.

Do we need to prepare for the test?

The test is simple so that the only attention to be made, in the case of a saliva swab, is not to introduce substances into the mouth in the 30 minutes prior to the collection .

So NO to foods, sweets, alcoholic or sugary drinks, coffee or tea, drugs such as syrups or effervescent substances, mouthwashes, cigarette smoke. Drinking water is allowed .

In summary , the genetic test for lactose intolerance is a non-invasive tool approved by the scientific community and offered by the main hospitals to investigate the body's predisposition to digest lactose.

It is a safe test regarding the result but it does not return confirmation of the fact that the discomfort that can be had today , if not repeated for some time, are caused by a permanent intolerance as we may not be intolerant today but become intolerant in the short term and the symptoms that we have come from other pathologies.

For this reason, we invite anyone who has the doubt of being intolerant to undergo a cheaper lactose intolerance Breath Test first and then, possibly, a DNA test.

In another article of our Blog you will find the description of the H2 Breath Test for lactose intolerance.

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Bibliography

• Understanding DNA, Third Edition: The Molecule and How it Works 3rd Edition by Chris R. Calladine, Horace Drew, Ben Luisi, Andrew Travers.
• Excellent agreement between genetic and hydrogen breath tests for lactase deficiency and the role of extended symptom assessment. Pohl D, Savarino E, Hersberger M, Behlis Z, Stutz B, Goetze O, Eckardstein AV, Fried M, Tutuian R. Br J Nutr. 2010.
• Excellent agreement between genetic and hydrogen breath tests for lactase deficiency and the role of extended symptom assessment. Pohl D, Savarino E, Hersberger M, Behlis Z, Stutz B, Goetze O, Eckardstein AV, Fried M, Tutuian R. Br J Nutr. 2010.
• Adult-type hypolactasia genotyping in Northern Italy: prevalence of C / T-13910 polymorphism and questions after comparison with existing data. Ghidini C, Sottini A, Zanotti C, Serana F, Marini M, Caimi L, Imberti L. Minerva Gastroenterol Dietol. 2010
• Effect of C / T -13910 cis-acting regulatory variant on expression and activity of lactase in Indian children and its implication for early genetic screening of adult-type hypolactasia. Kuchay RA, Thapa BR, Mahmood A, Mahmood S. Clin Chim Acta. 2011
• Meta-analysis: the diagnostic accuracy of lactose breath hydrogen or lactose tolerance tests for predicting the North European lactase polymorphism C / T-13910. Marton A, Xue X, Szilagyi A. Aliment Pharmacol Ther. 2012