+353 (1) 685 6929 Amelogenin is the sex-determining gene and is therefore found on both the X and Y chromosomes. When DNA testing is carried out on the X and Y chromosomes, females will display a single peak for both X chromosomes whilst males will display two peaks, one on the X chromosome and one on the Y-chromosome. The amelogenin gene is tested in cases where there is a mixed sample of DNA to verify whether there is only male DNA, only female DNA or a mix of both. In a Paternity DNA test many ISO accredited laboratories test a number of genetic markers; however, one of these markers is the amelogenin gene which will establish whether male DNA or female DNA is being tested. In this case, it is a precautionary measure that genetic analysts take lest should the oral swabs have been mixed up and placed in the wrong envelopes (thus for example placing the father’s samples in the mother’s envelope). The test of amelogenin gene can fail in very rare cases where for example, the male fails to have the marker on the Y-chromosome and can results in gender misclassification.