DNA Y-STR Typing is an Important Tool to Solve Criminal Cases

International Journal of Biotech Trends and Technology (IJBTT)
© 2019 by IJBTT Journal
Volume - 9 Issue - 1                          
Year of Publication : 2019
Authors : S.G. Pawar, V.S.Harel, B.P.More, K.V.Kulkarni

MLA Style: S.G. Pawar, V.S.Harel, B.P.More, K.V.Kulkarni "DNA Y-STR Typing is an Important Tool to Solve Criminal Cases" International Journal of Biotech Trends and Technology 9.1 (2019): 15-21.

APA Style: S.G. Pawar, V.S.Harel, B.P.More, K.V.Kulkarni (2019). DNA Y-STR Typing is an Important Tool to Solve Criminal Cases. International Journal of Biotech Trends and Technology, 9(1), 15-27.


The POCSO (Protection of Children Sexual Offence), 376 (sexual assault),302(murder) cases are on a rise in India and so are the cases where men are falsely implicated for the same. Many cases go unreported owing to the social stigma attached. There have been cases where women misused these laws for personal gains. Mixtures of body fluids and/or tissues from a male and female are frequently encountered with sexual assault casework and other violent crimes. These mixed samples often contain trace quantities of male DNA present in a large background of female DNA. Typical samples can include vaginal swabs containing a small number of sperm cells, body swabs from female victims of oral assaults, and fingernail scrapings/clippings from female victims of violent assaults. Standard autosomal STR analysis may be unable to detect the minor male contributor in these types of samples, while the 17 Y-STR loci techniques can routinely detect a minor male contributor present at less than 1:1000. In POCSO sexual assault cases the minor victims becomes a wide range of target by accused. In such cases rape cum murder also becomes a new fashion of psycho mind accused to destroy the evidence. We present a similar case study where the crime showed signs of violence. The male-specificity makes the Y chromosome especially useful in cases of male/female cell admixture, namely in sexual assault cases. On the other hand, the haploidy and patrilineal inheritance complicates the interpretation of a Y-STR match, because male relatives share for several generations an identical Y-STR profile. The presence of Y-peak on Amelogenin locus in Identifier STRs in vaginal swabs of victim raised doubt of case being positive but Y-Filer STR helped in distinguishing the male contributor from the alleged accused. This conclusion strongly indicates the power of Y-STRs in forensic DNA analysis –it not only helps in identification of perpetrator. The Y-filer technique is a powerful tool for the analysis of sexual assault cases that contain a suspect(s). A significant proportion of DNA cases contain a suspect who has been identified by conventional law enforcement techniques. For these cases, the Y-filer technique is a powerful tool that can be used to include or exclude a suspect(s) associated with an investigation.


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Forensic science; Rape cum Murder case; Y-STR; DNA typing