Personal Genomics

Personal genomics [jee‐noh-miks] (sequencing and analysis of the genome of an individual) employs several techniques, including single-nucleotide polymorphism (SNP) analysis chips (typically 0.02% of the genome), or partial or full genome sequencing. Once the genotypes are known, the individual’s genotype can be compared with the published literature to determine likelihood of trait expression and disease risk. 

Automated sequencers have increased the speed and reduced the cost of sequencing, making it possible to offer genetic testing to consumers. 23andMe sells mail order kits for SNP genotyping. The information is stored in a user profile and used to estimate the genetic risk of the consumer for over 240 diseases and conditions, as well as ancestry analysis.

Gentle is one of the newest players in the personal genomics field. They offer the most comprehensive genetic test on the market today, screening for over 1700 genetic conditions. The Gentle test also checks for personal genetic risks like breast cancer, colon cancer, aneurysms, and heart diseases. Gentle can also predict how a person will respond to certain medications, avoiding adverse drug reactions. Gentle offers genetic counseling by default, avoiding one of the most important criticisms on personal genomics companies.

Full sequencing of the genome for the purpose of personal genomics has been criticized by some clinicians because it can identify polymorphisms that are so rare that no conclusions may be drawn about their impact, creating uncertainty in the analysis of individual genomes, particularly in the context of clinical care. Czech medical geneticist Eva Machácková writes: ‘In some cases it is difficult to distinguish if the detected sequence variant is a causal mutation or a neutral (polymorphic) variation without any effect on phenotype. The interpretation of rare sequence variants of unknown significance detected in disease-causing genes becomes an increasingly important problem.’

There is a heavy debate as to how relevant the results of personal genome kits are and whether or not the ramifications of knowing one’s predisposition to a disease is worth the potential psychological stress. There are also three potential problems associated with the validity of personal genome kits. The first issue is the test’s validity. Handling errors of the sample increases the likelihood for errors which could affect the test results and interpretation. The second affects the clinical validity, which could affect the test’s ability to detect or predict associated disorders. The third problem is the clinical utility of personal genome kits and associated risks, and the benefits of introducing them into clinical practices.

Doctors are currently conducting tests for which some are not correctly trained to interpret the results. Many are unaware of how SNPs respond to one another. This results in presenting the client with potentially misleading and worrisome results which could strain the already overloaded health care system. This may antagonize the individual to make uneducated decisions such as unhealthy lifestyle choices and family planning modifications. Moreover, negative results which may potentially be inaccurate, theoretically decrease the quality of life and mental health of the individual (such as increased depression and extensive anxiety).

There is also controversy regarding the concerns with companies testing individual DNA. There are issues such as ‘leaking’ information, the right to privacy and what responsibility the company has to ensure this does not happen. Regulation of the area is not clearly laid out. What is still not determined is who legally owns the genome information: the company or the individual whose genome has been read. There have been published examples of personal genome information being exploited. Additional privacy concerns, related to, e.g., genetic discrimination, loss of anonymity, and psychological impacts, have been increasingly pointed out by the academic community as well as government agencies.

Conversely, sequencing one’s genome would allow for more personalized medical treatments using pharmacogenomics; the use of genetic information to select appropriate drugs. Treatments can be catered to the individual and the certain genetic predispositions they may have (such as personalized chemotherapy). Pharmacogenomics is both predictive and precise; genetic information may allow physicians to tailor therapy to a given patient, in order to increase drug efficacy and minimize side effects.

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