This survey was performed at a pre-conference workshop of the Southern Africa Society of Human Genetics in Cape Town during August 2019 – Prior to the introduction of point-of-care DNA testing and genome sequencing training at a skills development workshop at the Tygerberg Academic Hospital, from 26-27 September 2019.
It will be very convenient to have a rapid, affordable POC test available that can alter patient care with access to clinical intervention and genetic counselling support.94% AGREED
POC screening for founder mutations is important in the context of ancestry and family history.
The detection rate of BRCA1/2 founder mutations is reducing due population diversification, therefore a population-specific POC test will not be useful.
Often the report is provided when the patient has already started therapy or had surgery and that defeats the purpose of genetic testing.
When patients cannot afford panel testing founder mutation testing will be better than nothing, knowing the limitations related to population-based testing.
From a private practice perspective, a BRCA1/2 POC test will not be widely used as founder mutation testing is hardly ever requested anymore.
Founder mutation analyses are still first line testing for many conditions in the state sector and may therefore be used widely in government hospitals.
POC technology is very exciting and may be worthwhile for offering it to other conditions where common causative mutations have been identified.
A POC test will be extremely beneficial in paediatric genetic conditions (especially metabolic disorders) where immediate treatment is life-saving.
When a patient is going to pay for a genetic test out of pocket, most of the patients prefer rather going for the more comprehensive Invitae panels the first time around rather than having to do more than one test later.
With regards to BRCA1/2 predictive testing, the waiting period for results from Invitae (1 week) is helpful in giving the patient’s time to mentally prepare for the results.
Same day delivery of BRCA1/2 results might be a bit daunting as these results have major implications with regards to the patients themselves, their reproductive choices and their children.
A pharmacogenetic POC test for BRCA1/2 testing will facilitate access to clinical trials on PARP inhibitors approved by the FDA for breast and ovarian cancer.
CYP2D6 genotyping is useful to avoid tamoxifen resistance, especially in BRCA2 mutation- positive patients and those considering the use of antidepressants that affect enzyme activity.
Uncertain about BRCA1/2 founder mutations unless we have known families, but it could certainly be used for Lynch founder mutations.
Use of a validated POC test already available in the UK for warfarin dosing is encouraged given the risk of bleeding and associated costs.
A missed genetic diagnosis of HBOC is unlikely with the use of a combination of tests ranging from a rapid POC diagnostic assay for known BRCA pathogenic mutations to Minion/whole genome sequencing using an integrated service and research approach for return of results.
Sanger sequencing is the gold standard for confirmation of results obtained using gene panels/MinION or whole exome/genome sequencing.
Genetic counselling is essential for POC genetic testing that may require extension to clinical sequencing when the results are uninformative.