Related Experiment Videos
Rare failures in the amelogenin sex test
M Steinlechner1, B Berger, H Niederstätter
1Institute of Legal Medicine, Innsbruck, Austria. martin.steinlechner@uibk.ac.at
International Journal of Legal Medicine
|June 12, 2002
Summary
The amelogenin sex test, used in forensic DNA analysis, showed a failure rate of 0.018% in a study of 29,432 males. This indicates a low but present error rate for this established forensic tool.
Area of Science:
- Forensic Science
- Genetics
- Molecular Biology
Background:
- The amelogenin sex test is a standard method in forensic science for sex determination.
- It is commonly included in commercially available polymerase chain reaction (PCR) kits.
- Reliability is crucial for DNA databasing and casework analysis.
Purpose of the Study:
- To evaluate the reliability of the amelogenin sex test in a large cohort.
- To determine the failure rate of the amelogenin sex test in phenotypic males.
- To investigate the characteristics of individuals who failed the amelogenin sex test.
Main Methods:
- Analysis of 29,432 individuals from the Austrian National DNA database.
- Application of the amelogenin sex test using PCR.
- Confirmation of results using alternative amelogenin primers.
- Amplification of Y-chromosomal Short Tandem Repeat (STR) markers.
- Amplification of a fragment of the SRY gene for phenotype confirmation.
Main Results:
- Six out of 29,432 phenotypic males (0.018%) failed to produce the Y-specific amelogenin PCR product.
- Five of these six samples yielded full Y-STR profiles.
- One sample did not amplify any Y-STR markers.
- All six samples tested positive for the SRY gene, confirming male phenotype.
Conclusions:
- The amelogenin sex test exhibits a low failure rate (0.018%) in phenotypic males.
- The SRY gene confirmation supports the male identity despite amelogenin test failure.
- While highly reliable, the amelogenin test is not infallible and may require confirmatory testing in rare cases.