+353 (1) 685 6929 The most accurate way of proving biological fatherhood is by means of DNA paternity tests, involving the analysis and comparison of the DNA of father and child. What if the suspected father cannot be contacted or refuses the test?
Biological paternity can be proved to within 99.99% accuracy by DNA screening using samples from both the child and the father. This means that both subjects must be available for the samples to be taken. What happens when either subject is not available for the sample to be taken?
In normal circumstances, there is rarely any reason why the child should not be available, but prospective fathers might be living or working abroad, and not easy to contact, they might be unwilling to take the test or even be deceased. In such cases there are ways in which the DNA paternity test can still be carried out.
How relatives can be used to establish paternity
In the absence of a sample from the father, it is still possible for biological paternity to be established through DNA testing on relatives of the child. Grandparents, aunts and uncles and siblings of the child can be used to determine the disputed paternity when a DNA sample from the suspected father is not available.
Known as relationship testing, these types of DNA matching are not always legally binding, but can be accurate enough for people wanting to know whether or not a specific person is liable to be the father or not. In many cases, results are so accurate that it would have to be an unlikely coincidence if they were not.
However, more is needed for legal purposes, such as legacies and inheritances. One test that has been used in DNA analysis of samples collected after sex offences, such as rape, is referred to as Y-STR, which refers to short term repeats of fragments of the Y DNA of male children, and it has to be stressed that this applies only to sons, and not daughters.
The Y chromosome occurs only in males. When the 23 chromosomes of the male and female sex gametes combine to create the 46 chromosomes of a human being, one chromosome from each gamete determine the sex of the individual. Male gametes (spermatozoa) contain either an X or a Y sex chromosome (about equal numbers of each) and the female gamete (ovule) only the X chromosome, so the X-Y combination is male.
The Y chromosome does not appreciably change down the male genetic lineage, and so can be used to determined paternity. Any male member of the suspected father’s blood-line can be tested for short-term repeating patterns in their Y chromosome to prove a direct relationship with both the child and his father. Brothers, nephews, uncles or grandfathers will all share these same repeats.
Do we need the father?
In this way, the paternity of male children can be proved in the eyes of the law, and the presence of the father is not necessary – just one of his male relatives. If you feel that this type of test might be needed, you should contact the laboratory you will be using and explain the circumstances, when you will be advise on the best course of action.
If Y-STR testing is needed they will inform you whether or not they can carry it out, and also of what other options are open to you. They will also arrange any legal stipulations, such as notarization of the sample collection and the security needed to transport it to the laboratory for the DNA paternity tests.