Lactose Intolerance DNA Testing
In the department of GENETICA DNA RESEARCH (EDTA) + Consent Statement, we can investigate whether there is a hereditary predisposition to lactose intolerance.
Method PCR + sequencing.
About the lactose intolerance test
"There is also a DNA test. Most don't know this. Neither do I. Neither does my family doctor. Recognizable story. My GP at first didn't know where to turn for a lactose intolerance test.
Finally sent to a hospital for an H2 test. Got 50 grams of pure lactose there to drink and they controlled for 3 hours how nauseous I got. What a torture.
Afterwards I was told by others that this is a fairly medieval way to test. The DNA test had existed for a long time, but was too expensive my GP thought. Afterwards the H2 test was just as expensive".
This test is only suitable for the detection of congenital (congenital) lactose intolerance.
This is the hereditary form of lactose intolerance. People with this form of lactose intolerance make no or very little lactase from birth. They also do not tolerate breast milk. This form of lactose intolerance remains for life.
Not digesting lactose properly does not give everyone symptoms. The development of symptoms depends on various factors such as diet and the composition of the intestinal flora (all bacteria that live together in the colon). Also the sensitivity of the colon can play a role. People who suffer from irritable bowel syndrome (PDS) have symptoms due to lactose intolerance more often than other people. However, PDS is not the cause of lactose intolerance.
Primary lactose intolerance is therefore not identified with this.
This is the most common form of lactose intolerance and results from insufficient production of the enzyme lactase. Lactose is found in small amounts in breast milk. Almost all infants produce enough of the enzyme lactase to properly digest lactose from breast milk. After the third year of life, the production of lactase decreases in many Africans, Asians, South Americans and Southern Europeans. In these countries, lactose intolerance is much more common. Western Europeans and North Americans generally continue to produce sufficient lactase. This form of lactose intolerance is called "primary lactose intolerance.
Secondary lactose intolerance also cannot be demonstrated by this test.
Lactose intolerance can also occur when the intestinal wall is damaged. For example, with (chronic) inflammation of the intestine, an intestinal infection, after intestinal surgery or after radiation of the intestine. The intestinal wall is no longer able to produce sufficient lactase. This form of lactose intolerance is called "secondary lactose intolerance" and can be temporary in nature. When the intestine recovers, sufficient lactase is produced again.
When is this test useful?
- chronic abdominal discomfort after consumption of cow's milk products
- irritable bowel
- Longer lasting abdominal complaints without a clear cause
- chronic diarrhoea of unknown cause
- familial known lactose intolerance
- doubtful finding of lactose tolerance test
- doubtful finding of the H2 breath test
Lactose intolerance is inherited as an autosomal recessive trait.
Some diseases you only get if you inherit a fault in the same gene from both parents. These are called autosomal recessive diseases.
In recessive diseases, the healthy gene is in charge. So if your father or mother has the error on one version of the gene, he or she is not sick. Because the other, healthy gene is in charge. So they have one version of the gene with, and one without the error. But they can pass on the mutation. They are carriers.
Only when your father and mother both have an error (mutation) in a certain gene can you get the disease. This is often unexpected, because your parents don't notice that they are carriers.
There is always a 25% chance that both parents will pass on the error. There is also a 25% chance that the child will not inherit the error, and a 50% chance that the child will be a carrier.
The word autosomal means that it doesn't matter if you are a boy or a girl. Boys and girls have the same chance of inheriting the disease.
About 10% to 15% of the Dutch population has this disease. In other countries and populations this number is much higher (Africa, Asia:> 90%, Italy: 50% to 70%).
The defect is located on chromosome 2q21. In 2002, this gene mutation was first considered to be the cause of lactose intolerance. In addition to lactose intolerance, it could be shown that calcium intake in milk and bone density (hip, lumbar spine) are also reduced.
The result is good if negative.
LCT-13910 genotype CC: hereditary adult lactose intoleranceLCT
13910 genotype CT or TT: no evidence of hereditary adult lactose intolerance.
For this DNA test a signed consent form is needed to allow your DNA to be analyzed by Laboratorium Stein for this test only. You will receive this consent form together with the test kit.