Reading the Genome

Reading the Genome

DNA sequencing allows us to read almost all of the more than three billion letters in your DNA sequence, determine their order, and detect subtle DNA changes, or typos, at almost every position. When the DNA letters change, it can alter the words within a gene and sometimes the instructions they provide.

Illumina sequencing technology does this by breaking the entire genome encyclopedia into smaller fragments of about 200-300 DNA letters each. Since humans are very similar, a reference human genome sequence can be used to help line the fragments up in the correct order. To make sure each individual DNA letter has been read correctly, each fragment is read many, many times.

The human genome sequence has about three billion bases, and each cell contains two copies of your DNA sequence, one inherited from your mother and the other from your father. A genotype describes the DNA bases present at a specific location in the two copies. With genotyping, only a certain number (1 to 100,000s) of specific DNA changes are assessed. If new DNA changes are discovered to be important after your genotyping has been completed, you will likely have to be genotyped again to learn about the new information.

With DNA sequencing, the entire sequence of your two copies is decoded. This tells you the order of DNA bases, or letters, over a larger area of the genetic code rather than focusing in on specific locations.

In some cases, sequencing is used to look at the genetic code within a single gene. With the Illumina TruGenome Clinical Sequencing Services, we analyze the entire genome sequence.

The data gained from your genome sequence can then be analyzed by genetic specialists, doctors, or researchers to learn how variations in your genome may impact you. Medical and research doctors' ability to analyze and interpret genome information is still quite limited. It is important to reanalyze data in the future to account for new discoveries and what they may mean in your genome.

Interested in receiving newsletters, case studies, and information on new applications? Enter your email address.

TruGenome Clinical Sequencing Services is performed in the Illumina CLIA (Clinical Laboratory Improvements Amendment)-certified and CAP (College of American Pathologists)-accredited Clinical Services Laboratory. The TruGenome Sequence information is generated by licensed personnel using an analytically validated process. Consistent with Laboratory Developed Tests, it has not been cleared or approved by the U.S. Food and Drug Administration.

This genome sequence information can be analyzed to potentially aid physicians in the evaluation of a broad range of health conditions or physiological traits. Patients will not receive medical results, or a diagnosis, or a recommendation for treatment from Illumina. Any results arising from the analysis of genome sequence information that might be deemed medically actionable should be confirmed using alternative testing. If any questions or concerns arise about what is learned through the genome sequence information, patients should contact their physician or a genetic counselor. Currently Illumina does not accept orders for TruGenome Clinical Sequencing Services from New York.