Molecular diagnostics entails the analysis of biomarkers to help diagnose, track the progression of, or determine risk factors and prognosis of disease. Biomarkers have been identified within the realm of genomics, epigenomics, transcriptomics, proetomics, metabolomics, and lipidomics:
- genome: coding of protein sequences on DNA
- epigenome: modifications of genomic DNA and mRNA formation and processing
- transcriptome: microRNA and modifications of mRNA
- proteome: functional look at proteins
- metabolome: metabolites
- lipidome: lipids
The most accessible molecular diagnostics include traditional methods such as measuring blood pressure, cholesterol levels, blood counts; identifying antibodies and antigens in serum, stool, or tissue samples; and measuring viral load. This information is commonly collected using in-vitro diagnostic techniques such as immunoprecipitation.Advanced molecular diagnostics refer to the enhanced ability to peer into the genome, epigenome, and transcriptome via next generation sequencing and improved nucleic acid detection via digital PCR.
The key factor is using molecular diagnostics is to have a clear link between the presence of a biomarker and the development of disease. This requires the collection and analysis of large amounts of data, with consistency in handling and technique, and a high-powered method of data analysis. The advancement of technology has enabled the linkage of changes in the genome to specific biomarkers in the proteome, metabolome, and lipdome as well as to directly link certain genetic markers to disease. This information has changed the approach to cancer treatment; the diagnosis and therapuetic plan are tailored to each patients unique biomarkers to increase efficacy.
Next Generation Sequencing
Advanced molecular diagnostics are possible due to the decreasing cost of genomic sequencing and ability to analyze single nucleotide polymorphisms (SNP) across a wide population. In order for these techniques to work we need a large pool of healthy and diseased people to find SNPs and genomic patterns that can identify or predict disease. We now have the ability to look directly at specific SNPs to determine and individual’s chance of developing a disease. One example is a known mutation in the BRCA1 or BRCA2 tumor suppressor genes. If a patient knows that she has this mutation she will be more likely to detect cancer early and able to live a longer and healthier life. Advanced molecular diagnostics is all about using technology and vast amounts of patient data to find patterns, and it has changed the way doctors predict, diagnose, and treat disease. We have entered an age of individualized health care.
The rise in popularity of individual DNA testing kits for tracking ancestry and health traits has made rudimentary genetic sequencing technology available to everyone. The vast amounts of genetic data that are generated via these services will have to be dealt with in the future; this is particularly a concern when balancing healthcare privacy and access to data generated by private companies. While the positive side to individualized healthcare is that targeted treatments are possible, there is a dark side in that medical insurance could be tailored to charge more money for individuals whose genetic code has more risk of disease. As individuals we will have to weigh the risk versus the reward of having our genetic information available. As a society we will have to consider who can access this information and how it can be used. How far will we take this knowledge, and how will we lay down ethical guidelines for dealing with the vast amounts of personal information provided by genetic sequencing?