Y-STR , or Y Chromosome Short Tandem Repeats, is another testing method we offer. Y-STRs are found only on the male-specific, Y chromosome. The Y chromosome is inherited through the paternal line and remains virtually unchanged through many generations. By examining specific locations on the Y chromosome, we can generate a Y-STR profile for each male tested. Males who are related through their fathers will tend to have the same or similar Y-STR profiles, and males who are not related will likely have different Y-STR profiles. |
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Areas of use in Y-chromosome testing: |
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When an alleged father is not available for testing, male relatives of the alleged father can be used as a reference; only male children can be tested via this method. |
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When a mother is not available for testing, the Y-STR method can be used in conjunction with nuclear DNA STR testing
to prove paternity (i.e., mutation cases); again, only for male children. |
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In forensic cases, when a mixture is present… |
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...where either more than one male may be present, it can be used to determine the number of males present; |
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...a male and female mixture is present, the male sample can be masked due to the high concentration of female sample; the Y-STR method will ignore the female portion of the mixture, and only focus on the male sample.the male sample. |
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If there is a missing male person, male relatives can be used as a reference to provide a DNA match. |
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| What does a Y-STR chromosome match mean? |
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Two individuals that share the same Y-STR haplotype are very likely related through the same paternal line. |
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Example:
If male A has a Y-STR haplotype that matches the Y-STR profile found in an unknown sample, then male A cannot be excluded as being the donor to that unknown sample. In addition, all patrilineal relatives of male A cannot be excluded. It may also be true that an unknown number of unrelated males may not be excluded as being the donor of that unknown sample. |
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