The Amelogenin Sex Gene in Dna Paternity Testing

DNA testing is now the most widely used method for determining the biological relationships between individuals. The DNA paternity test is probably the most widely known of these tests and involves the testing of an alleged father, mother and the child in question. This test can also be conducted just between Alleged Father and a child without the Mothers sample.

When performing the Paternity Test, most DNA testing laboratories will test a minimum of 16 genetic markers for enhanced accuracy levels in excess of 99.99%. One of these genes tested is called the ‘Amelogenin’ gene and its use is to determine the sex of the sample that has been processed. Therefore in reality the statistical analysis is actually based on the matching of 15 of these 16 markers.

From a biological perspective, males have an XY chromosome and females have an XX chromosome. Therefore in your DNA test result you should see an XY for the alleged father and the child if he is male, and XX for the Mother and child if she is female. A DNA paternity test result from any serious service provider should report this gene together with the rest of the genetic markers analysed.

Functions and Uses of Testing the Amelogenin Gene

The testing of this gene may appear superfluous to a client at first instance, however it does serve a number of functions.

1. From a laboratory perspective, it acts as a primary quality control check and ensures that the correct samples have been processed. So for example, if the Alleged Father’s sample turns out to be female, then there is an element of quality control to identify the possible reasons. These could include problems such as the client putting the wrong samples in the wrong envelopes (e.g. putting the father’s sample in the mother’s envelope and vice versa). The testing of this gene can also act as a deterrent for submitting someone else’s samples (having said that, this applies only if the sample of someone of the opposite sex is supplied).

2. Gender identification through DNA testing has also got applications in the field of forensic DNA testing as it provides primary information regarding samples found at the scene of the crime during a criminal investigation. Through the test, it is possible to confirm whether biological remains found at the crime scene belong to males or females. It is also possible to differentiate this even in cases of mixed samples.

3. Gender identification is also applicable in the case of infidelity DNA testing. Analysis of the samples will show whether suspicious stains belong to a male or female individual. On the basis of this result, decisions for further testing can be based.

However, gender identification by amplification of the amelogenin gene can sometimes generate a result in which male samples were falsely identified as females. I have myself only seen few of these cases over the years. This occurrence is therefore very rare and occurs in less than 0.01% of cases in males and even less in females according to some studies. In such cases, it is suggested to perform the Y amplification of SRY gene or/and Y-STR markers to confirm the gender

Want to Live an Extra 10 Years?

Paternity Testing: A Blessing or a Curse

The jury is still out on whether the now easily available paternity tests are a blessing, a blessing in disguise or a curse.

            The School of thought which holds that paternity testing is a blessing will argue that the easy availability of DNA-based paternity tests has had a liberating effect on both men and women. For the men, a simple DNA-based paternity test offers opportunity of knowing – for sure – whether the child they are setting up to bring up is indeed theirs’ or whether they are having games played on them – a piece of knowledge which many of our men forefathers would have given anything for. Through such a DNA test, paternity, like maternity, becomes a certainty – beating the age old adage where maternity was said to be almost always a matter of certainty, with paternity always being seen as matter of presumption. For women too, paternity testing offers the opportunity of nailing men who go around fathering children and the abdicating their paternal responsibilities. Now while before the advent of DNA-based paternity testing the courts could dismiss the woman’s case (where she happened to suing for child support) on account of lack of enough evidence, the modern woman armed with a DNA test result showing the man in question to be the child’s father has a far better chance of success in her case.   

On the other hand, the school of thought which holds the view that paternity testing is a curse argues that such testing has destabilized the classical approach to parenthood; an approach which many feel was serving us just as well. In this classical approach to parenthood, having children was appreciated for its social value, rather than physical value. In this regard then, people had children to keep their ‘names’ – rather than their genes – alive. Of course our innate longing – according to way we have been programmed by the creator, was to move our genes to the next generation through our children, but since there was no way of knowing that whoever you were bringing up was indeed your gene-bearer (especially for the men), a person had to content themselves with having some to take their ‘name’ to the next generation. All that has changed with the advent of paternity testing – and all one has to do today is to take a simple DNA test, and they are well on their way to knowing if the person they call their ‘son’ or their ‘daughter’ is indeed their gene-bearer or simply a ‘name-bearer.’ Now the implications of knowing a person you have all along being treating as your offspring is nothing of the sort can be devastating to say the least, even if the person in question happens to be just a young child – as DNA tests are typically carried out on young children in dispute. So devastating, in fact, are the effects of the realization that the person you have been treating as your child is nothing of the sort that people have been known to do things they would never have thought of doing before – either to themselves or to the child in question – upon realizing that the child they have always thought was their was not. Of course the proponents of DNA based paternity testing will counter this argument with the fact that the all a DNA test does is to reveal the truth, and it is better to live with a bitter truth, than with a ‘sweet’ lie.

Want to Live an Extra 10 Years?