Genetic testing has convicted many criminal offenders. In the past, these tests have not yielded definitive proof for identical twins since their genetic fingerprints differ only minimally from each other. A simple forensic test would not be able to distinguish one twin from another. Therefore, criminologists had to sequence the complete genome of both twins to detect individual changes such as mutations that may have occurred during the course of life. In some cases, they may have had to analyze DNA methylation patterns, which are also modified in the course of life due to the individual lifestyles of monozygotic twins. Also, DNA methylation patterns differ immediately after the birth.
Both of these methods, however, are too expensive for everyday forensics. Fortuitously, British biochemists recently discovered how to track the different epigenomes of genetically identical samples with just one simple test. The researchers simply heat-denatured the DNA derived from five identical twin pairs. Since the melting curve for the heat denaturation depends on the DNA methylation patterns, the genetically same samples could be distinguished from one another with so-called high-resolution melt curve analysis (HRMA).
Source: http://www.newsletter-epigenetik.de/
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