A clinical approach to genetic testing for non-specialistsBMJ 2017; 358 doi: https://doi.org/10.1136/bmj.j4101 (Published 28 September 2017) Cite this as: BMJ 2017;358:j4101
All rapid responses
I noted the article on genetic testing for non-specialists with great interest; increased genetic literacy amongst front-line healthcare professionals is of huge import due to the dramatic increase in range and scope of DNA genetic tests performed in the NHS is now underway but also because genetic testing is much ore widely in established than many realise due to lack of agreement of the term "genetic testing". The article gave a narrow definition of a genetic test; - “a process where this DNA is sequenced to look for changes in genetic makeup” with no reference as to source. I suggest that this is an incomplete definition and that the more appropriate definition of " a genetic testing" is that is given by the US National Institutes of Health which highlights that genetic tests are widely in use already and that genetic testing is not solely the terrain of those who run DNA testing services:-
“Genetic testing is a type of medical test that identifies changes in chromosomes, genes, or proteins. The results of a genetic test can confirm or rule out a suspected genetic condition or help determine a person’s chance of developing or passing on a genetic disorder…. Several methods can be used for genetic testing:
Molecular genetic tests (or gene tests) study single genes or short lengths of DNA to identify variations or mutations that lead to a genetic disorder.
Chromosomal genetic tests analyze whole chromosomes or long lengths of DNA to see if there are large genetic changes, such as an extra copy of a chromosome, that cause a genetic condition.
Biochemical genetic tests study the amount or activity level of proteins; abnormalities in either can indicate changes to the DNA that result in a genetic disorder.”
National Institutes of Health: Genetics Home reference: US National Library of Medicine @ https://ghr.nlm.nih.gov/primer/testing/genetictesting (accessed 18.10.17).
In my view genetic testing has been undertaken at scale, for example by screening laboratories, for some while. For example, in 2002 I led the establishment of a National Genetic screening programme which is now successfully embedded in the NHS in England and detects and counsels thousands of genetic carriers each year – the NHS Sickle Cell and Thalassaemia Screening programme. (https://phescreening.blog.gov.uk/category/sct/) .
The NIH definition implies that genetic tests are widely in use already and that genetic testing is not solely the terrain of those who run DNA testing services. It highlights why increased genetic literacy for ALL healthcare professionals is important now, and the importance of developing a realistic and affordable approach to counselling of individuals about genetic findings informed by understanding of genotype phenotype interactions.
It also emphasises that genetic education of the whole population is ethically important to ensure that individuals have a good understanding of what the implications of findings are, before they have to face difficult choices rather than in the middle of such a situation, in particular as common gene tests for relatively common conditions such as Sickle Cell and Familial Hypercholesterolemia re performed not just DNA tests for rare variants. A quick scan of the internet will show that a range of definitions of genetic testing are used.
A common definition which we all agree is an important and early step in getting communication clear both for professionals and also importantly the public as genetics is recognising as "for us all" and not only "for experts".
Competing interests: I set up and ran the NHS Sickle Cell and Thalassaemia Screening programme between 2001-2013. This is genetic screening programme which highlighted many aspects and challenges relating to genetic testing.