The Golden Age of Health and Wellness is Almost Here
A recent article in the Vancouver Weekly News describes the euphoria that accompanied the official declaration of the completion of the international human genome project, a consortium of over one thousand scientists worldwide.
The project began in 1990. It was a monumental task to sequence 3.2 billion bases of DNA that constitute an entire human genome. All the information needed to build an organism is contained in a genome.
When, in the year 2003, scientists announced the project’s completion, it was thought that the “golden age” of health and wellness had begun.
Genome Sequencing 2019
The process of whole-genome sequencing provides a comprehensive map of human genetic makeup and analysis of genes. But by 2019 most scientists admitted that diseases and gene expressions were much more complicated than initially envisioned.
On a more positive note, the fact that sequencing costs are now significantly lower means that anyone has an opportunity to have their genome sequenced. This new way of consumer testing is already being provided by several companies. Customers pay a small fee, send in the kit with their DNA sample, and receive their genomic data.
About Direct-To-Consumer Testing
Many of the promises by these direct-to-consumer (DCT) companies never materialized. The companies advertised that consumers would receive “incredible” data on their medical risks and ancestry. The results were mixed.
The methods used to develop the tests rendered them either helpful, unclear or extremely misrepresentative.
Decoding someone’s DNA and searching for abnormalities is dependent upon the resources used and the time spent on processing such a huge amount of information.
3.2 Billion Nucleotides
This brings us back to the 3.2 billion nucleotides that are aligned to form patterns (genes) that build protein products. Research is currently focused on finding out whether a disruption in these patterns also will also disrupt a vital biological function.
An individual nucleotide disruption is called a single nucleotide P\polymorphism (SNP). This is what the DTC companies are testing.
Yet there is a drawback to DTC testing in that it is restricted to searching for patterns that have already been recognized.
The process used in DTC testing searches one region on the DNA to identify the nucleotide residing there (genotyping). DTC tests only search 600,000 regions or about 0.2% of the DNA.
There is considerable uncertainty surrounding DTC testing. Therefore the government regulators do not allow DTC tests to provide risk assessments to consumers based on DNA genotyping.
An Expert Opinion
Dr. Jill Hagenkord is a molecular pathologist and has been associated with several tech startups such as color genomics and 23andMe. Dr. Hagenkord explains that her reason for stressing caution with respect to DTC testing originates from her experience with the HFe protein that is associated with iron storage disease.
In a recent interview, Dr. Hageord said that her team believed that they could identify people who were at risk for the iron storage disease hereditary hemochromatosis (HHC).
They eventually discovered that HHC was not as widespread as they originally thought. Therefore screening became impractical. In addition, when an expansive test of purportedly high-risk people was performed to identify the abnormalities, only 2% of the tested population was shown to be at risk. It is noteworthy also that at this point there are no other confirmatory tests if a person’s DNA sequence shows an abnormality.
The Challenge of Assessing Predictive Value
Measuring a test’s ability to carry out its intended mission is complicated by the fact that genotyping algorithms (rules for problem-solving) are not yet perfected.
A computer must be capable of detecting abnormalities. The key here is that it must first be exposed to a sufficient number of abnormalities in order to identify them.
Dr. Theodora Ross, a University of Texas molecular pathologist, believes that at this current stage of development, it is not possible to instruct an algorithm to accurately and reliably detect disease.
He agrees that genome testing has a promising future. He also agrees with Dr. Hagenkord and other experts who say that in order to determine proof of illness, they should not yet rely entirely on genome testing.
