The World Leader in Private DNA Testing

As DNA testing technology advances, it seems that there are new types of DNA tests available nearly every week. Biotechnology companies are offering DNA tests that they say can show a person’s genetic predisposition to many physical characteristics and can even link heredity and illnesses. DNA testing can also help establish a person’s identity in criminal cases, and individuals’ DNA profiles can be compared to determine if a biological relationship exists between them. Many types of DNA testing have made media headlines recently, and through this post DDC hopes to clarify differences between these various DNA tests.

Currently, DNA testing can be divided into several categories. Three of the categories most prevalent in the media recently are Genome Analysis, Gene-Specific Analysis (commonly referred to as Genetic Testing) and DNA Identity Testing (under which paternity testing falls). What differentiates the tests into these three categories is the portion of DNA that scientists examine during testing.

Inside each cell within a living organism, there are tightly bundled strands of DNA, which stands for Deoxyribonucleic Acid. DNA strands are often referred to as “the building blocks of life,” because it is DNA that contains the basic instructions for how each living thing grows, develops and changes over the organism’s course of life.

Each strand of DNA resembles a double helix or twisted ladder shape. The “rungs” on the ladder are made up of pairs of nucleotides. These pairs of nucleotides occur in a pattern specific and unique to each individual, and make up the “code” that influence an individual’s physical features and predisposition to illness. A person’s entire set of DNA code is said to be his “genome.”

Genome Analysis is the study of a person’s genome as a whole. Much like when one reads a book and notices a common theme throughout the chapters, scientists examine the entire “story” of a person’s genome to see if he or she is predisposed to certain illnesses of characteristics. Some companies may offer to determine your entire genome sequence (arrangement of all the nucleotides on your DNA) or they may offer to examine hundreds of thousands of locations on your DNA to create a “genomic profile.” The applications may vary; for example, according to personal genomics companies, Genome Analysis could predict an individual’s risk of certain diseases like heart disease or diabetes, or trace hereditary characteristics such as food preference or sleep patterns. This category of DNA testing is a very new development in the field, and many experts are currently debating the merits and impact of this type of testing.

Within the human genome are genes, which are segments of the DNA strand that code for specific traits. Unlike Genome Analysis in which scientists examines the a person’s genome as a whole, in Gene-Specific Analysis scientists examine an individual gene that is associated with a specific disease, such as breast cancer or cystic fibrosis. This type of DNA testing is typically requested by a physician in the course of diagnosis; also, when a family member is diagnosed with one of these inherited diseases, doctors or genetic counselors can test other family members to see if they too carry the gene. Some companies are beginning to sell these tests directly to the consumer; concerns are being raised about having access to this information without the benefit of genetic counseling.

There are other regions on the DNA that may not necessarily code for specific physical characteristics, but rather play a structural role on the DNA. An example of these non-coding regions are portions on the DNA that are composed of short, repeating sequences of DNA, called Short Tandem Repeats. These STRs have certain characteristics, such as size, that can be used to determine a person’s identity or prove family relationships. Each individual inherits a certain set number of these STRs from each biological parent. This enables scientists to use these DNA markers for DNA identity testing, the third category of DNA testing that is often mentioned in the media today. Scientists can compare a child’s alleles with those of his or her parent to determine maternity, paternity, and other family relationships. Scientists use this kind of analysis in family relationship testing like paternity tests, and can also use STR testing to identify individuals in forensic cases as well.

For more information on how DNA paternity testing works, please click here.

This entry was posted on Wednesday, April 16th, 2008 at 1:12 pm and is filed under DNA Paternity Testing. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.