Genetic testing — how to know what you don’t want to know.

Genetic testing becomes more common, due to the development of cheaper sequencing technologies, and the growing popularity of inexpensive direct-to-consumer (DTC) genetic testing services. Eventually, most people will undergo genetic testing, not only those with clearly elevated genetic risks. Only recently, Geisinger Health System (GHS), a physician-led health care system in the US, announced that they intend “… to sequence every single patient who comes through the door at Geisinger.” There are good reasons for this approach, genetic testing has some significant benefits, exemplified by a recent paper published by Buchanan and coworkers in the journal Genetics in Medicine1. Their study describes the impact of identifying likely pathogenic BRCA1 and BRCA2 genetic variants in patients who previously didn’t have cancer and were at an age to receive risk mitigating strategies. Out of 26 people who underwent a screening procedure over a 1-year follow-up period, three patients were indeed diagnosed with an early-stage BRCA1/2-associated cancer, demonstrating that screening for pathogenic gene variants among unselected individuals can lead to early disease detection with the potential to intervene at a disease-state when it is still possible.

But what about situations where we cannot intervene with medications or lifestyle changes? For certain diseases we do not yet have a cure, nor can we prevent it; one example is Huntington disease (HD). The disease is a hereditary condition which severely affects the brain and nervous system. The symptoms usually do not occur until people are in their forties or older. The disease is inherited in an autosomal dominant pattern, meaning an affected person has a 50:50 chance to pass the mutation that causes HD to the children. It is this type of information that some healthy, high-risk individuals prefer not to know. Usually, individuals who have a family history and are considering predictive testing should meet with a genetic counselor. Testing for HD is technically easy, but the implications and emotional aftermath of the results are usually anything but straightforward.

However, genetic testing gets more complex with the appearance of whole genome sequencing (WGS); the future of genetic testing. In WGS, all the approx. 3.3 billion base pairs in the genome are sequenced and can potentially provide insight about disease risk. Here, sophisticated algorithms are needed that can filter out those results that we don’t want to know. By providing educational material plus smart contracts on the blockchain (that define those filters), we can make the decision process much easier. To give an example, a person with a family history of breast cancer and HD could specify to be informed about any cancer risk, while no feedback, not positive nor negative, is given in regard to HD. With the rise of WGS testing, any DCT genetic test service provider should empower individuals with easy to understand information to help them evaluate genetic testing options. That is the reason that we at Shivom aim at developing solutions that help people become better informed and to support independent decision-making around these very emotional and personal testing decisions. To help doctors, researchers, and anyone else who deals with genetic testing navigate that minefield, Shivom aims to provide evidence-based information combined with smart contracts. Smart contracts are self-executing contracts with the terms of the agreement between parties being directly written into lines of computer code. The code and the agreements contained therein exist across a distributed, decentralized blockchain network. Using smart contracts, people can decide if they want to learn about their risk of developing certain diseases or not.

. With the rising interests in common and complex diseases genetic testing, it is certain that there will be an exploding need for genetic counselors in complex diseases in the coming few years2. This is one reason why we also aim to build a large global genetic counselor network. Genetic counselors will be responsible to provide education and risk interpretation for consumers as well as supporting health promotion models. Today, there is only one certified genetic counselor for every 80,000 Americans; the situation is even worse in other parts of the world where the profession of genetic counselor is almost unknown.
A global network of genomic/health counselors.

As genomic data become more common in the clinic, it is imperative that clinical scientists and physicians use automated and standardized tools which employ up-to-date methods and curated literature content. Optimizing and standardizing the analysis and interpretation of genomic data means reducing the opportunity for human error and ensuring that interpretation is robust and reproducible by basing it on a foundation of trustworthy scientific content.

References

1. Buchanan, A. H. et al. Early cancer diagnoses through BRCA1/2 screening of unselected adult biobank participants. Genet. Med. gim2017145 (2017). doi:10.1038/gim.2017.145

2. Wang, M. H. & Weng, H. Genetic Test, Risk Prediction, and Counseling. Transl. Informatics Smart Healthc. 1005, 21–46 (2017).

3. Shelton, C. A. & Whitcomb, D. C. Evolving Roles for Physicians and Genetic Counselors in Managing Complex Genetic Disorders. Clin. Transl. Gastroenterol. 6, e124 (2015).

— By Dr.Axel Schumacher,CEO of Project SHIVOM.