DNA TESTMany of you have already performed a family dna test. What are they? How are they done? What information do they bring? How to use them?What are they? There are actually several dna tests. The more common test is to analyze markers (and not all dna) of dna included in the parents-transmitted chromosomes, half being transmitted by our mother and the other half by our father. This has its importance in family genetics, because when we identify a match with another individual, unless you know the family relationship, the test does not inform on the (maternal or father) side of the relationship. Two more tests can be useful and are much less frequently performed: haplogroups of Y chromosome (passed from father to son) and of mitochondrial DNA (transmitted by the mother to her children - daughter or son).How are DNA tests done? The sampling is usually done by collecting cells from the inside of the cheeks using a stem (kind of cotton stem). It is completely painless and perfectly sufficient to perform the test. The collection material is sent to you by the company you have chosen to practice this test.What information does dna tests bring? They allow you to determine your ethnic origins and identify other individuals ("genetic cousins") with DNA that matches yours. These results are given to you in the form of probabilities. They are more reliable if the family relationship is close and the society-specific database that carried out the test is important (for ethnic origins). To multiply the chances of finding genetic cousins (or "matches"), I advise you to transfer your results to several sites of genetic genealogy (Gedmatch, myheritage, familytree dna, etc...).How to use these results? To determine if a cousinship is on your maternal or paternal side (in the absence of known family connection), the best way is to test a close member of your maternal family and a close member of your maternal family. You will then be able to determine which side of your family this genetic cousin matches. The other way is to look for the common matches between you and this "cousin". In addition, all genalogic genetic websites give you the opportunity to contact your matches by email. If you have the name of the "cousin" (some people use alias), look for them in Geni, you may have the chance to establish the family bond thanks to their tree.However, for Moroccan Jews there are several obstacles:1. The number of Moroccan Jews tested is still low (compared to Ashkenazi, for example) and the current available databases still contain too few Moroccan Jews.2. Our ancestors have traveled a lot and our origins are multiple (Spain, Portugal, Middle East, Ashkenazi). This can result in unexpected and perhaps not always reliable results, due to the low number of Moroccan Jews in existing database.3. As in most Jewish communities, lot of Moroccan Jews have married cousins (endogamy). It is not rare to find in our community cousins both on the maternal and father side. This increases the intensity of DNA matching between 2 individuals making it difficult to establish the level of cousinship.