When the father isn't available, other family members' DNA holds the answer
Genetic relationship analysis between siblings, grandparents, uncles, and other family members.
Test details
The family relationship test analyzes DNA from the alleged father's relatives — siblings, parents, uncles — to determine biological relationship with the child. The more family members participate, the higher the accuracy.
How does it work?
Contact us to evaluate your specific case
We determine which family members can participate
We send kits to each participant
Receive results in under 7 days
How does a family relationship test work?
When the alleged father is not available, the bond can be confirmed by testing other relatives: grandparents, siblings, aunts and uncles. Each person's STR marker profile is compared from a saliva sample taken with a cheek swab.
Samples are collected
A cheek swab from everyone involved. It doesn't hurt, requires no fasting and can be done at any age, from newborns to older adults.
Genetic profiles are compared
The lab analyzes how many markers the tested people share and whether that pattern of matches is consistent with the relationship being confirmed.
The likelihood of the bond is calculated
Unlike a direct paternity test, the result is expressed as a kinship index: how likely the proposed relationship is compared with the people being unrelated.
- Useful for grandparentage, siblingship (half or full) and aunt/uncle with niece/nephew.
- Including the mother or other relatives greatly increases the certainty of the result.
- These tests give a high probability, not the 99.9999% of a direct paternity test; in some cases adding Y-chromosome or mitochondrial DNA analysis is recommended.
If the alleged father can take part, a direct paternity test is always preferable. The family relationship test is the alternative when that is not possible.
Frequently asked questions
Which family members can participate?
+Is it as reliable as a direct paternity test?
+What types of samples do you accept?
+Other tests in this section
Write to us and we'll walk you through which one fits your case and what it costs.
Paternity test
Buccal swab from the alleged father and the child. Results in under a week, available as informational or legally valid.
See details →Non-invasive prenatal paternity
From week 10 of pregnancy, using cell-free fetal DNA in the mother's blood. No procedure touches the baby.
See details →Genetic carrier panel
Checks whether a healthy person carries recessive variants — cystic fibrosis, spinal muscular atrophy, congenital deafness, among others — that only cause disease when both parents pass on the same one. It is done before trying to conceive or during the first trimester. It is not a paternity test; it answers a different question.
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