Summary The easy availability of genetic profiles has revolutionized human identification to solve criminal cases and to determine biological relationships of kinship, common paternity. The short tandem repeats, better known as STRs are the most widelyused genetic markers for this purpose. A DNA profile consists of genotypes for a number of STRs, which are almost unique code to differentiate or relate to a person biologically. Currently the lab is based on three techniques: 1) DNA extraction, 2) multiplex PCR, and 3) capillary electrophoresis, and there are commercial kits to easily develop this task. In paternity is expected to enter the DNAprofile of an alleged father (SP) and child (H) there is at least a match for each bookmark. When more than one marker no correlation between SP and H provides an exclusion and the result is virtually unquestionable. However, when everything matches between SP and H biostatistics should make an assessment of the case, estimating the probability that another individual picked at random from thepopulation to match the child. To this must be studied STR markers in the population where they do DNA testing, to use the allele frequencies of STRs in the biostatistical analysis. In this estimation is called paternity index (PI), which indicates how many times more likely to have found the SP-H line whereas it is the father, for that was an individual picked at random from the population. This IP canbe transformed into percentage of paternity (W), to facilitate interpretation. There are specific formulas to calculate the IP, which change depending on the genotype of each marker analyzed, according to the paternity case, whether participating or not the mother, if not the father but they are the grandparents, if one doubts the paternity of both parents, etc... In Mexico, these studies thatsupport its proper implementation is often more concerned that not enough trained personnel, both in the laboratory and in the administration of justice, always ensure the correct interpretation of the evidence on scientific grounds.
Introduction In 1985 Alec Jeffreys implemented the use of genetic material (DNA ) for human identification, obtaining a band pattern similar to a barcode which hecalled DNA fingerprint (DNA fingerprinting) (Figure 1). Currently this test is called DNA profiling, genetic fingerprinting, or just DNA testing. This DNA profile has been shown to be
virtually unique and unrepeatable, with the exception of monozygotic twins , which allows anyone to differentiate from each other and establish their biological relationships of kinship. The applications ofDNA testing are diverse, but two stand out, paternity testing and forensic analysis, the latter in criminal cases to establish the relationship of a suspect with the evidence left at the scene of a crime (eg. blood or semen stain) to incriminate him or, where appropriate, release them. Other less common applications are to establish family relationships of corpses in cases of disaster or missingpersons, historical research (eg. Remains of the Romanov family, origin of Columbus, etc..), Or in anthropology to analyze human populations to study its origin and evolution. This review of DNA testing will focus on its application in paternity, checking for this basic aspects of the human genome and molecular marker techniques to obtain a DNA profile, biostatistical aspects for the interpretationof results issued by a laboratory, and frequently asked questions about DNA testing.
Figure 1. Alec Jeffreys, who invented the use of DNA for human identification in Leicester, UK. In the background is observed DNA fingerprinting (DNA fingerprinting) and Jeffreys called the pattern of bands obtained, similar to a barcode, presumably unique to each individual.
Human Genome The structure of...