Basic Facts About DNA and Its Testing
DNA – deoxyribonucleic acid is a double helix structure (looks like twisted ladder). Human Genome Project (HGP) has done automatization of human DNA. Human DNA has been physically mapped by HGP.
DNA Tests are done basically for –
To find out genetic defects of certain diseases. For example DNA screening is done in Jewish population for autosomal recessive neurodegenerative storage disease Tay-Sachs disease which has reduced the number of affected individuals.
In legal system to confirm identification of dead body, to find out rapists, to find out biological parents in disputed cases, to determine culprit from samples which investigators collect from crime scene.
In scientific research.
(DNA Testing is also called DNA fingerprinting, because probability of error with DNA testing is one in 30 billion, which means there will be practically no error at present because world population at present only little above 6 billion which is way below the accuracy figure of DNA testing.)
DNA Testing(Genotypic Analysis) is done by fragmenting of double helix structure of DNA & sequencing them in a particular sequence. DNA is the vehicle of transport of genetic material & information from parents to offspring’s in entire animal & plant kingdom except some RNA(ribonucleic acid) viruses where RNA is the vehicle of transport of genetic material. In other cases RNA cannot act as a vehicle of transport of genetic material.
The accuracy of dna tests has caused wide acceptance & application in the field of medicine & also in judiciary. Genetic engineering has revolutionized the pharmaceutical industry which applies recombinant DNA technology for large scale production of drugs at a very cheaper rate.
DNA Testing requires very minute quantity of material for testing which is very important for crime investigation, because sometime the quantity of sample is very minute in quantity. A single cell or a single root of hair is sufficient for DNA testing. DNA testing can also be done in very old samples which require only few cells.
Prerequisites for success of dna testing screening in field of medicine includes the following : the disease should be potentially serious, that it can be influenced at a presymptomatic stage by changes in diet, behavior and/or by pharmaceutical manipulations, that the screening test does not result in any harm or discrimination.
DISADVANTAGES OF DNA TESTING
It may cause discrimination, for example screening for Sickle cell trait/disease in African Americans has led to unanticipated problems of discrimination by health insurers & employers.
Cost is very high & requires highly skilled manpower.
Some diseases like Cystic fibrosis can be caused by few hundred different mutations, which become difficult to determine exact mutant gene.
DNA Testing should be used judiciously to take optimum benefit & it should be used more frequently in judicial / legal system to deliver speedy better judgment.