This Amelogenin gene is responsible for determining sex in an individual and is found on both the X chromosome and the Y chromosome; the latter Y chromosome only found in males. DNA testing companies often test 21 loci on the DNA samples provided. However, out of these 21 loci, one of them is the amelogenin gene which is tested as a precautionary measure and as a way to ensure reliability of results. In some cases, people doing the test might misplace the swabs by putting the father’s DNA sample in the daughter’s envelope. Testing this gene, means that such errors are detected and amended by the laboratories carrying out the test. Genetic testing of this gene is also done by forensic teams when bodies have decomposed is a way that does not allow gender to be determined by simply looking at the remains. In very rare cases in males, there is what is known as a deletion on the Y chromosome of the amelogenin gene; this means that male DNA samples will results as being female DNA samples; however, this phenomenon is so seldom that it need not be of concern to anyone wishing to take a DNA test.