DNA Databanks

DNA Databanks

With the advent of significant biotechnological advances in molecular biology, particularly with the completion of the human genome sequence, a better understanding of the genetic material that we inherit (DNA ) has allowed scientists to utilize this information in a variety of applications. One of these ways has been to initiate and establish large-scale DNA databanks. A DNA databank is essentially a storage facility that maintains DNA extracted from a variety of sources from an individual including blood , saliva , hair, skin, or other kinds of tissue (muscle, liver, etc). Since DNA in the proper storage conditions can be maintained indefinitely, creating DNA databanks can serve a variety of purposes that include screening for disease genes, paternity testing, identity matching for criminal investigations, and research-related studies.

The initial incentive for creating DNA databanks was to have a repository to send out samples for molecular genetics testing to screen for genetic predispositions to disease or inheriting disease genes. Currently, the United States lacks a DNA databank with a national, centralized repository system. Other countries such as Iceland, the United Kingdom, and Estonia have established large, centralized DNA databanks on a national level. An essential method to better understanding disease as it relates to the human genome has been to link DNA databanks to clinical information so that researchers can elucidate the mechanisms of heritable disease, susceptibility to disease, and identify ways to use the genome for therapeutic applications.

A national DNA databank in the United States has been controversial due to the ethical, legal, and social implications. These issues revolve around the fear that a national DNA databank will compromise an individual's privacy and give law officials too much accessibility to an individual's genetic information. Furthermore, having DNA stored in a national DNA databank risks misuse of the DNA in the future, even if initially there are carefully considered restrictions and the appropriate informed consent. Genetic information is analogous to anthropometric or biometric medical information. However, it is much more robust in terms of the information it contains.

Although a national DNA databank does not exist in the United States, most states collect DNA from convicted murderers or sex offenders. All states have a law regarding the storage of specific DNA information from any individual arrested or convicted of a felony in a database and a small percentage of states require the DNA profiles of all felons to be in this database. DNA has linked murderers to the crimes they committed retrospectively, in some cases decades after the murder was committed. In these cases, a national DNA databank would have significant ramifications in law enforcement. DNA identified at the scene of the crime could be matched to an individual within hours after the sample is analyzed. This would only be possible if the entire country underwent DNA fingerprinting and these findings were stored in a centralized database that law enforcement officers could use to match to DNA found at a crime scene. This would allow rapid identification of suspects and lead to a larger number of arrests. The cost for such a large-scale endeavor is considerable.

Currently, DNA databanks for forensic purposes utilize a standard DNA-typing system based on the Federal Bureau of Investigation (FBI ) panel (13) of specific DNA markers called short tandem-repeat loci, or STRs. STRs are DNA sequences that are repeated a different number of times in different individuals. These repetitive sequences are inherited and can be used to identify an individual with a high degree of certainty. The DNA data is processed using a universal system known as the Combined DNA Index System, or CODIS . All states are expected to comply with this system and criminals who cross state lines, if their DNA information is stored in the database of genetic profiles, can be identified by any referral center that has the expertise and access to the system. The DNA information that stored is predominantly for the purposes of identification, no other genetic information is stored on the databases. CODIS DNA profiles are used for a dual law enforcement purpose. While one purpose is to store profiles of convicted felons based on states' requirements, the other is to collect and store unidentified DNA profiles that are from specimens obtained at crime scenes. Although the states maintain their own databanks, the FBI coordinates crosstalk between states through a searchable National DNA Index System, or NDIS .

CODIS is responsible for making over 500 matches, leading to arrests by establishing a connection between different violent crimes or by matching a suspect's DNA to DNA obtained from a crime scene using known convicted felons genetic profiles from the database. Over 1,000 crime investigations have benefited from CODIS since its inception. There are over 104 laboratories in 43 states and the District of Columbia. NDIS has assisted the FBI to link six sexual assault cases occurring in the District of Columbia to cases in Florida that otherwise would likely have remained unsolved. It is important to recognize that a significant percent of matches are linked to genetic profiles obtained from criminals arrested for crimes that are not felonies, suggesting that minor crimes are repeated with an increasing magnitude of offense.

see also DNA fingerprint; DNA profiling; DNA sequences, unique; DNA typing systems; Mitochondrial DNA typing.