Talking about the present scenario, we all are aware how unsafe our society is for children and women. There has been an alarming increase in the child missing reports registered in different parts of the world. According to a report published by The Indian Express, around 22,567 children went missing out of which 12,999 were traced back in 2019 and according to Delhi Police PCR around 17-12 (2019-2020) kids goes missing everyday which is very traumatic for the loved ones and the relatives of the children. It shows how many loop holes are there in our law enforcement agencies. There can be varied reasons for missing children like abduction or kidnapping by someone, human trafficking, child willingly leaving his/her home, etc. Now the question arises, after retracing the missing child what is the most appropriate methodology to establish the identity of that child? DNA is the answer to this question. Be it paternity testing, identification of the victim or suspect from the analysis of biological evidences or the determination of identity of the child, DNA solves all these peculiar problems quite efficiently. DNA is present in each and every cell which forms a human body and about 99.9% of the DNA is similar in all the human beings. This 0.1% variation is the soul of DNA analysis which makes us unique and gave rise to DNA fingerprinting (developed by Sir Alec Jefferys) which can be used to correlate or differentiate between two people.
The base pairs in 0.1% variation of DNA constitute up to three million base pairs (bp) which is enough for generating a DNA fingerprint unique to an individual. It works on the availability of minisatellites, restricted fragment length polymorphism (RFLP), mtDNA (mitochondrial DNA) and Short tandem repeats (STRs). Traditionally DNA analysis was done based on minisatellites which are 10-60 bp long stretches of DNA and RFLPs that showed great variation from person to person. The first step involves isolation of DNA from the human cells (blood, saliva, sweat, hair follicles) followed by incubation with restriction enzymes. These enzymes are also known as molecular scissors which play a vital role in this process of DNA analysis. These cut the DNA chains at different positions resulting in pieces of DNA differing in lengths. Now these pieces of DNA are allowed to run on the gel where they gets separated on the basis of charge and molecular mass. The standard sample of DNA is also allowed to run parallel along with the suspected sample to establish or negate the similarity between the two.
Modern DNA analysis is done based on STRs or microsatellites as for RFLPs, more amount of sample (more than 25 ng) that too undisturbed was required which is not possible in every case. Say for example if a dead body of a child is recovered after hundreds of years, the body will be completely deteriorated and the DNA sample due to sunlight and UV rays will also get damaged which will be difficult to analyze if the cut in the length occurred due to enzyme or it was damaged due to external factors. STRs are 2-4 bp repeats like 5’GATAGATAGATAGATA3’ (GATA STR), 5’TATATATATATATA3’ (TA STR). These are repeated in the human genome many a times forming variable lengths of repeats in every individual. It requires comparatively very less amount of DNA sample which are amplified using PCR (polymerase chain reaction) to produce greater number of DNA copies containing STR regions. After amplification of STR containing regions of DNA copies production, they are made rum undergo gel electrophoresis and where fragments separate on the basis of their size.
Establishing a “LINK”
Now that we know how the DNA fingerprinting is performed, it is easier to understand that how a person could be detected on the basis of DNA found on the crime scene. Other than that, DNA analysis establishes a link between the suspected person and his /her relatives commonly called as paternity testing. The child gets his or her half DNA from his/her mother while the other half from the father. Thus, the STRs present in the cells of the child is a combination of their parents. This very information passed on becomes the base for identification of a person and establish if someone is the biological parent or biological child of a person. Due to its very high success rate, it has been continuously used for the identification of children who goes missing.
Children are very innocent and should be protected in all the ways possible and from all sorts of abuses, for example; Human trafficking for child labor, child pornography, abduction for money by family members or others and worst female genital mutilation along with child marriages.
The reported number of cases are quite high but there are cases where complaints are not even registered meaning thereby that the actual number of missing cases is even more than that.
To fight crimes against children a program called DNA-PROKIDS was launched internationally at University of Granada. This program was divided into three tiers. First tier maintains the national level genetic database consisting of DNA profiles of children who were involved in illegal situations like not living with parents due to kidnapping, abduction, etc. and the DNA profiles which were voluntarily given by family members of the missing children. This database was used for comparison and identification of missing children. Pilot studies of this program occurred in Guatemala and Mexico with efforts being made in Brazil and China also.
There are several case studies where is seen that the infants are stolen from the hospitals and even in a young age from their homes and sold for money to couples who are unable to conceive. In such cases, the child if retraced back after years need not look like what he/she looked when she/he was abducted. Here DNA analysis is the most robust approach for revealing the true identity and establishing their true roots.
In New York, Carlina Netty White was abducted from as an infant from the hospital. After two decades, after having her own child, she was shocked and became suspicious when her own mother was unable to show her the birth certificate of hers. This suspicion rose to heights and she began searching for her true roots, her identity which took her to a website. On that website she found a photograph of an infant that was missing which resembles to her own childhood pictures. Later, DNA analysis confirmed her suspicion to be true, the photo was of Carlina only and she was further reunited with her parents (biological ones).
This case study shows how DNA analysis proved that the child who went missing 20 years ago was Carlina White and helped her reach to her real parents.
Photo courtesy- https://mysteryu.com/age-progression-photos/2/
DNA is the most appropriate and robust approach for detecting the remains of missing children and even identifying the long lost kids who could be reunited with their families by analysis of their DNA samples. It joins the two unknown variables with each other on the basis on STRs, mtDNA, minisatellites, etc. It doesn’t need any other confirmatory tests or analysis to support the findings, while it’s like a one man army and is enough to reveal the identity of missing children on its own called as DNA fingerprinting. The whole technique is based on the fact that the DNA of a person is combination of their parent’s genetic material and hence tracing back the genetic composition of a person to its roots of any missing child is possible. 25th April is celebrated as National DNA day every year and it wouldn’t be wrong to say that witnesses might die, people may lie, memories might fade away or even families will away but DNA never ever go away, it holds to its true roots and thus DNA analysis is the answer to the questions of any loved one seeking justice.
- Alvarez-Cubero, M., Saiz, M., Martinez-Gonzalez, L., Alvarez, J., Eisenberg, A., Budowle, B., & Lorente, J. (2021). Genetic Identification of Missing Persons: DNA Analysis of Human Remains and Compromised Samples. http://dx.doi.org/10.1159%2F000334982
- Buś, M., Schellberg, T., & Budowle, B. (2019). Human trafficking – Multinational challenge for forensic science. Forensic Science International: Genetics Supplement Series, 7(1), 403-405. doi: 10.1016/j.fsigss.2019.10.029
- Finding Missing Kids: It’s in Our DNA. (2021). Retrieved 6 March 2021, from https://www.missingkids.org/blog/2020/finding-missing-kids-its-in-our-dna#:~:text=DNA%20is%20what%20solved%20this%20case.%E2%80%9D&text=Here%20at%20NCMEC%2C%20in%20the,resolved%20using%20DNA%2C%20Schweitzer%20said.
- What is a DNA fingerprint?. (2021). Retrieved 6 March 2021, from https://www.yourgenome.org/facts/what-is-a-dna-fingerprint#:~:text=DNA%20fingerprinting%20is%20a%20technique,identical%20twins%20is%20very%20small.
- DNA Fingerprinting – an overview | ScienceDirect Topics. (2021). Retrieved 6 March 2021, from https://www.sciencedirect.com/topics/immunology-and-microbiology/dna-fingerprinting
- them, F. (2021). Frightening statistics on missing children put Delhi police on a mission to find them. Retrieved 6 March 2021, from https://www.newindianexpress.com/cities/delhi/2020/aug/17/frightening-statistics-on-missing-children-put-delhi-police-on-a-mission-to-find-them-2184413.htm