We offer a personal, confidential DNA testing service in the Manchester, Stockport and Cheshire areas in conjunction with DNA Clinics Ltd. Here are the answers to some frequently asked questions.
What is DNA testing?
DNA (deoxyribonucleic acid) is present in every cell of the body containing a nucleus. Each person’s DNA is composed of genes inherited from both mother and father. Certain regions in the DNA molecule show variations between people making it chemically unique to each individual (except for identical twins, who have identical DNA).
The DNA test compares parts of the alleged parent’s DNA with that of the child. We also offer a full range of other DNA relationship tests.
How long will I have to wait for the results?
The laboratory analysis of your samples and interpretation of the results is a painstaking, time consuming task. The standard in-laboratory time is 7–9 working days. We understand that you may be anxious to know the results, but telephoning us will not speed up the process!
Please allow for postage times, weekends and bank holidays on top. We also offer express processing.
Will the test prove a relationship?
DNA tests can only rule people out. When a child’s DNA does not match that of the alleged parent, this proves with 100% certainty that they could not possibly be related. We say they are excluded.
When the DNA does match the child’s, strictly speaking we can only say
that they are ‘not excluded’ as the parent. This is because there is a possibility (albeit statistically remote) that someone else is the biological parent. In everyday terms a matching result is conclusive.
Sibling and Grandparentage analysis is never as conclusive as parentage analysis. A typical result might be 0 - 5% probability of a relationship (strong evidence that a relationship does not exist) or 85 - 99% (strong evidence that
it does). However, there is a possibility with Sibling and Grandparentage tests that a result in the 30 - 70% range is obtained – which is inconclusive.
What happens if a conclusive result cannot be obtained?
In rare cases where the outcome does not produce strong evidence one way or another, you can opt for an extended study in which the DNA from the
original mouth swabs is subjected to additional analysis. There is a further fee payable.
What helps to increase the probability of paternity?
Certain factors determine the degree of statistical probability that the matching DNA does indeed show a relationship. The greater the number of participants, the better the statistical probability will be. Also, the greater the
number of genetic locations analysed by the laboratory, the more accurate the result. Our laboratory compares no less than 16 parts of the DNA molecule (warning – not all labs do!). If this is carried out, and both parents’ DNA is analysed, the probability of a ‘not excluded’ parent being the actual parent will exceed 99.9999%. (Compare this figure with the statistical accuracy of 99.9% required to convict an individual of a crime.)
However, this figure is based on the assumption that close relatives of the tested man (such as brothers) are not possible fathers. If this assumption cannot be made, the probability will be lower. This is because the possibility of a relative (eg brother) of the biological father matching the child's DNA is much higher than that of a random man in the population. For this reason, you should mention it when attending the clinic if this applies in your case.
What DNA samples are used for paternity or maternity testing?
A sample is taken from inside the mouth of the child and both parents. Contrary to popular belief, what is required is not saliva, but actual skin cells from the cheek which rub off easily and painlessly using a specially designed ‘buccal swab’ (cotton bud).
Can twins have different fathers?
Yes. If a woman has sex with two men at short intervals within the same
ovulatory period, so-called ‘heteropaternal superfecundation’ may occur.
I want to test someone’s DNA without them knowing. Can you help?
No. Having human tissue with the intention of its DNA being analysed, without the consent of the person from whom the tissue came, is unlawful under the Human Tissue Act.
Wouldn’t blood samples be more accurate?
No. A person’s blood cells and skin cells contain exactly the same DNA so there would be no benefit in using a blood sample.
Why do you ask for the mother’s DNA in a paternity test?
It is important that both parents’ DNA is sampled to determine which genes in the child were inherited from the mother. The remaining genes must have been passed down by the child's biological father (paternal genes). The tests can then focus on just these genes.
It is still possible to conduct the test without the mother’s DNA, but we do normally require her written consent in any case. A motherless paternity test reduces the accuracy of the test and in very rare cases, produces
Why do you need to know the ethnic group?
In order to calculate the probability of a relationship, it is important that we know the probability of genetic markers matching just by chance. A ‘positive’ test result will be expressed something like this:
“It is 19.9 billion times more likely that the alleged father is the biological father of the child than an unrelated man of similar ethnic origin.”
Different ethnic groups have different random match probabilities.
What does the fee include?
Our fees are per case and are fully transparent with no hidden extras. They include written results for each participant over 16 years of age, either:
- given to you at a half hour Results Session back at the clinic with your
- delivered to you by post. If you choose Express processing, then the laboratory can telephone you with the results.
Can a second man be tested later without re-swabbing the child?
Unfortunately, no. Unless the first test was Court Approved, a complete new
test must be done.
Do you offer DNA testing for Court purposes?
Yes. All of our tests are available as a legally accredited DNA test. Legal DNA tests and Peace of Mind tests are equally accurate. If you don’t need to go to court, choose the cheaper Peace of Mind DNA test.
Can I trust the laboratory you use?
The UK based state-of-the-art laboratories specialise in human identification applications (DNA Profiling), which utilise the latest in DNA technology and genomic amplification. Genetic technology is constantly evolving and the laboratories ensure they remain at the forefront of these changes to ensure unparalleled accuracy of results.
They adhere to the voluntary Code of Practice set out for genetic testing
laboratories. By employing the latest ABI Prism technology they deliver the most discriminating fluorescent STR-based assays available, for human identification applications. This places them at the cutting edge of this specialised area. All the equipment and reagents used in the laboratories are validated by and/or comply with regulations set out by CODIS (Combined DNA Indexing System) ENSFI (European Network of Forensic Science Utilities).
What about confidentiality?
DNA testing is a personal matter. We respect your privacy and we take steps to protect your personal information. For this reason, if you telephone us regarding your case, you will be asked for certain personal information to identify you. We will not discuss any aspect of your case with a third party (including your relatives) unless you have nominated them in writing at the time of your consultation.
What if I need counselling?
Counselling can be helpful and supportive in dealing with feelings which may arise before and after the test is carried out. We are all trained and experienced counsellors and are happy to discuss you options at any time. Counselling is not included in our DNA testing fees.
We will be happy to answer any further questions you may have. Please contact us without obligation. If you wish to speak to a scientist directly for technical or impartial advice concerning a DNA test please call 0800 032 5945 during office hours.