How does it work?
It all starts in the cells that can be recovered from your saliva sample and that contain your genetic information. The first step of our analysis is to extract and isolate the DNA from your cells. These molecules are then amplified, that means that, many copies are made. This process is important to ensure that we have your information with the highest quality and quantity possible, free of any contamination.
The DNA is placed on a glass slide, called a microarray, which has the DNA probes that correspond to the 700,000 single-nucleotide polymorphisms (SNPs) of the Illumina GSA platform. Your information is contrasted against the microarray probes, which allow us to determine your genotype for each of those SNPs. Those are the data we finally use to determine your genetic ancestry and your one-parent lineages.
To calculate your ancestry percentages, we assembled a reference panel of public genetic data from populations around the world, representing genetic diversity at the continental level. These populations are:
- North Africa: Morocco
- East Africa: Bantu, Kenya
- West Africa: Mende, Sierra Leone & Yoruba, Nigeria
- South-West Europe: Spain, France, Italy
- Western Europe: England, Scotland, CEU
- Eastern Europe: Hungary, Romania
- Northwest Europe: Lithuania, Russia
- Northern Europe: Finland
- Jews: Ashkenazi Jews & Sephardic Jews
- Middle East: Lebanon, Syria, Turkey
- South Asia: Gujarati, India & Telugu, India
- East Asia: Han, China & Japan
- Southeast Asia: Kinh, Vietnam & Cambodia
- Oceania: Papua New Guinea & Melanesia
Our ancestry test differs from other commercial tests in which we include Latin American populations and we provide you with how much of your genome looks like these populations:
- North America: Pima, Zapotec, Nahua, Maya
- Amazonas: Karitiana, Brasil & Surui, Brazil
- Andes: Quechua, Peru & Aymara, Peru
By comparing your genotypes with those of the reference panel, you can assign an ancestry to each of your SNPs and calculate a percentage of ancestry for your entire genome. It is important to note that although the methods we use are robust and have a minimum margin of error, the estimates we present are approximations and are dependent on the reference panel in this analysis. Also, these percentages should not be interpreted as direct belonging to the populations used as a reference, since they only represent how much of your genome resembles the populations used in the analysis and does not imply that you have phenotypes or cultural characteristics of them.
Finally, in the GSA microarray there are specific SNPs that are found in mitochondrial DNA and in the Y chromosome. We use the positions of your mitochondrial genome, which are different from the reference genome and a database to determine your maternal lineage / haplogroup. In the specific case of men, with the SNPs of the Y chromosome, we examine which sites are informative to define your paternal haplogroup.
Behind the genetic test of SOMOS is a team of experts in genomics of human populations with wide international recognition ...
Genetic information contained in the genome can tell us so much more aspects besides ancestry, which contribute to each person being unique. For example, it is possible to assess the risk to certain diseases or traits ...
The genome is the set of genetic material that we inherited from our parents and is usually analyzed in three areas because each one tells us complementary stories about the ancestors of a person ...