The worldwide projects on scanning the human DNA are leading to the conclusion that a large number of diseases are actually linked to the genetic composition of an individual. With the advancement of gene-scanning technique, since 2005, studies have linked as many as 40 common chronic diseases, such as, diabetes, arthritis, cancer, blindness, heart attack, multiple sclerosis, gallstones, etc to nearly 100 DNA variants. New discoveries on genetic variants and their association with diseases are evolving nearly everyday.
The new studies are not benefiting the common person for the time being as there has been no startling therapy that could prevent genetic diseases for the time being. Nonetheless, genome-wide association (GWA) uses genotyping technology to assay hundreds of thousands of single-nucleotide polymorphisms and relate them to clinical conditions. However, the GWA studies have some important limitations that include possibility for false-positive and false-negative results, biases related to selection of study participants and genotyping errors.
Scanning the DNA is a difficult task that requires sieving through a large volume of data present in the chromosome of the cell. DNA is made of long sequences of building blocks that contain the genetic information. It consists of two long chains of nucleotides twisted into a double helix and joined by hydrogen bonds between the complementary bases adenine (A) and thymine (T) or cytosine (C) and guanine (G). Five years ago, the Human Genome project that was a global collaboration of international research institutions was able to complete the identification of all the building blocks in the human DNA. Currently, new studies and DNA-scanning technology is working on finding genetic links to diseases.