Relationship DNA tests
When the possible father can't take part, his relatives can. The same tests answer questions about siblings, twins and mothers.
- Sibling DNA test
Full siblings, half siblings or not related.
- Grandparent DNA test
When the father can't take part, his parents can.
- Aunt or uncle DNA test
When the father's brother or sister can take part.
- Twin DNA test
Identical or fraternal, from a cheek swab.
- Maternity test
Confirms the biological mother.
Which relative to test
A child shares about half of their DNA with each parent. The closer the relative who takes part, and the more relatives who take part, the clearer the answer.
| Who can take part | Test | What to expect |
|---|---|---|
| The father's parents | Grandparent DNA test | The strongest answer when both grandparents take part. |
| The father's full brother or sister | Aunt or uncle DNA test | Less certain than a grandparent test; the mother taking part helps. |
| Another child of the father | Sibling DNA test | Shows full, half or no shared parents; a known parent taking part helps. |
| Twins | Twin DNA test | Shows whether twins are identical or fraternal. |
| A possible mother | Maternity test | Confirms whether a woman is the child's biological mother. |
Each test can be done with a kit at home for your own answer, or with a witnessed collection when you need it for court. See paternity tests without the father.