Your DNA Test in 5 Steps
Order online
Order your DNA test online and add your options if necessary.
We ensure activation with the partner laboratory.
Receive your instructions by email
No kit is sent.
You will receive all instructions directly by email: client codes, forms, procedures, and the laboratory address.
Collect samples at home
Easily perform your home collection using a simple buccal swab to collect a saliva sample.
Send to the laboratory
Place your samples in paper envelopes and send them to the laboratory following the instructions provided in the email.
Receive Your Results
Receive your results by email within a few days.
Options
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Additional participant: +99€
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Non-standard sample (hair, nails...) : +69€
Deadlines
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Buccal swabs: 5-7 days after receipt
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Non-standard samples: 10 days or more
Garanties
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Analysis of 21 genetic markers
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100% reliable for negative results
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99.9% reliable for positive results
Who can participate?
The X chromosome test is based on the genetic transmission specific to the paternal lineage. In a female, one of the two X chromosomes always originates from the father, and this paternal X chromosome is itself inherited from the mother of the father.
As this chromosome remains virtually unchanged across generations, all women descended from the same biological father share this X chromosome in common.
Thanks to this characteristic, the analysis allows for the verification of whether two women are descended from the same father, even in the absence of the latter.
By extension, when the father is not available, it is also possible to establish paternity by comparing the X chromosome of the daughter with that of the paternal grandmother, who is the direct source of this chromosome transmitted to the father and then to the child.
Sisters
Whether they are full sisters or half-sisters, the test remains valid regardless of whether they share the same biological mother.
Grandmother - Granddaughter
The paternal grandmother may also participate in the test: by comparing her DNA to that of her granddaughter. It is possible to verify the paternal lineage.
Mother (optional)
In some cases, the DNA of the biological mother of the sister or granddaughter may also be requested to clarify X-chromosome transmission and strengthen the analysis.
The analysis conditions
The interpretation of an X chromosome test depends on the family situation. Depending on the presence or absence of the biological mother and the exact relationship between the participants, three scenarios are possible.
Both sisters share the same biological mother.
If the sisters share the same mother, her participation is essential to obtain reliable results.
Maternal DNA enables the laboratory to correctly isolate the genetic contribution from the father and to analyse solely the paternal X chromosome.
In cases of uncertainty regarding maternity or if maternal DNA is unavailable, it is advisable to consider a sibling test, which is better suited to this situation.
The two sisters do not share the same biological mother (half-sisters).
When the participants do not share the same mother, maternal DNA is not mandatory.
The X chromosome test remains reliable, as the X chromosome inherited from the father is easier to identify and compare between half-sisters.
However, the participation of the mother may be requested to enhance the analysis.
X Chromosome Testing between a Paternal Grandmother and Her Granddaughter
A comparison between the paternal grandmother and her granddaughter allows for the verification of the paternal lineage.
The grandmother transmits an X chromosome to her son, who then passes it on to his daughter: their DNA therefore contains the same X chromosome from this lineage.
This test provides a clear and precise answer regarding the paternity of the granddaughter, even in the absence of the biological father.