Microsatallites

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Importance of microsatallites for identity testing and disease diagnosis :
Microsatallites :
- Microsatellites are di, tri, or tetra nucleotide tandem repeats in DNA sequences. The number of repeats is variable in populations of DNA and within the alleles of an individual.
Importance microsatallites for identity testing :
- Microsatellites can be used as markers in genetic studies of linkage in families and linkage disequilibrium studies of populations. In linkage studies one can examine large number of families and see when the alleles of specific markers are inherited together with a phenotype in more cases than not. Microsatellite repeat are amplified with fluorescently labeled primers and then the alleles from each individual in a family …show more content…

As a result of the above features, microsatellites can be used for personal identification, population genetic analysis and construction of evolutionary trees. In addition, they are located in several important gene loci and this allows microsatellites to be used as markers of disease and to provide information about individual gene status, especially in tumors. This can be accomplished by assessing allelic imbalance or loss of heterozygosity of a particular gene by analysingmicrosatelliteslocated at specific loci in the gene. Recently, mutations within microsatellites have been described as a result of defective DNA repair mechanisms, resulting in the phenomenon of microsatellite instability. This has been implicated in the aetiopathogenesis of several hereditary and non-hereditary conditions. There are several ways of analysingmicrosatellites, the popular using radioactively-labelled primers and autoradiography. This method has several drawbacks, especially the use of radioactivity and interpretative/technical problems. The use of fluorescently-labelled primers, automated DNA sequencing coupled with a computer software package obviates these problems. This technique has the added advantage of analysing several microsatellites in large numbers of cases, simultaneously. Thus, microsatellite analysis has become an important investigative tool for the molecular biologist and has provided new information in many