There’s a lot of talk right now about mainstreaming, in which all or part of the clinical genome testing process is handled by non-genetics health professionals, and there’s some seminal international research being done on developing various models of delivery.
The concept is not new. Mainstreaming was originally coined in the context of cancer genomics testing in the last decade, when gene panels for breast cancer and other inherited cancer genes became available to ordering and to being integrated into clinical practice through oncology services, not necessarily through the standard of care of clinical genetic services.
Prior to the availability of mainstreaming of genomic testing, the standard of care for many years has been to have the clinical genetics team primarily responsible for the management of patients and families with heritable conditions. The involvement of the clinical genetics service has included the continuum from assessment, through decision on appropriate testing, pre-test genetic counselling, test ordering and result disclosure, to patient and family management based on the available genetic information. In the standard of care, genetic pathology laboratories have provided testing services for patients referred exclusively by the clinical genetics team.
However, two factors have changed this equation.
Number one: disruptive genomics technologies which have brought mainstreaming closer to the patients and their families, because they provide more opportunities to do genomic testing at scale or at large to bigger populations, to bigger numbers of people.
The other factor contributing to mainstreaming is that the genomics clinical workforce has been relatively steady over the years. So, the greater demand for genomic services requires the involvement of other health professionals who help and facilitate the integration of genomic testing into patient management.
This year, there have been a few seminal papers in the medical literature, mainly from Canada and the UK, on proposed frameworks for how mainstreaming could be truly integrated into practice. The Canadians, for instance, determined four different models depending on how much or how little each of the non-genetic clinicians gets involved in this whole process.
In the traditional model, they don’t get involved at all. The only thing the non-genetic clinicians do is refer the patient; and everything else is managed through the genetics clinic.
The mainstreaming models have non-genetic clinicians involved, either partially or entirely, in the whole process of care delivery surrounding genomic testing performed by the genetic pathology laboratories.
One model has the non-genetics clinician taking all the history, understanding what type of testing is required for the patient, and ordering the test – but then the involvement stops there. Everything else is maintained by the clinical genetic service.
Another model has the non-genetics clinician ordering the test, receiving the results, providing all the counselling, pre-test and post-test. However, if testing of other family members is required, then the patient is referred to the clinical genetic service for that follow-up.
I would say from my experience over the last decade or so that various degrees of these models have been integrated into practice here. However, it all depends on various other factors.
To start off with, it depends on the characteristics of the patient and the disease. If the disorder or the family history or context is complex, then the non-genetics clinicians are less likely to engage in mainstreaming of genetic/genomic testing.
If, for instance, a patient has a well-defined genetically determined kidney disease, a nephrologist may be comfortable with ordering the genetic test and not engaging clinical genetic services. Whereas, if the disorder is more complex or syndromic involving other systems (let’s say eye, brain, in addition to the kidney), then they may decide it’s beyond their scope and refer the patient to clinical genetic services which – by default – are well versed in complex genomic disorders.
