Abstract
Purpose: :
Testing for the presence of a germline RB1 mutation can detect children and their family members at risk of developing retinoblastoma and second cancers, and those who may pass on that risk to future offspring. Genetic testing for retinoblastoma has reached a sensitivity of over 94% in Canada, but has been difficult to replicate elsewhere. In low-and-middle-income countries, high costs of testing mean that this part of patient care is inaccessible.Our purpose is to study the feasibility and efficacy of RB1 genetic testing in India, using a Global-to-Local collaborative approach, whereby the initial high sensitive detection is achieved in a central Canadian lab, and confirmation, interpretation, testing of family members and reporting is conducted locally.
Methods: :
Our pilot study cohort included 7 bilateral retinoblastoma patients presenting at the Narayana Nethralaya Eye Hospital in Bangalore, India. DNA was extracted by Qiagen kit at the local lab in Bangalore, and sent to Retinoblastoma Solutions in Toronto for clinical genetic testing. RB1 mutation detection was completed for each proband by sequencing and quantitative multiplex-PCR as previously described (Richter et al, 2003). Results were sent to local lab along with proband DNA, primers and protocol for confirmation in the proband. DNA from blood of parents and siblings was extracted and analyzed both in India and Toronto, comparing accuracy and efficiency of each site. Costs saved on EUAs deemed unnecessary by negative genetic testing on child relatives of probands will be calculated.
Results: :
DNA of sufficient quantity and quality for mutation detection was extracted by the local Bangalore lab. Proband RB1 mutations were detected for all 7 patients within 18 days of receiving the samples. Cost of proband mutation identification was less for batched samples than for samples sent and reported individually. Confirmation in the proband by the local lab and testing of family members in both labs is currently underway.
Conclusions: :
Using a global-to-local approach, RB1 genetic testing can be delivered in low-and-middle income countries in a cost-effective and efficient manner without compromising turnaround time or quality.
Keywords: retinoblastoma • genetics • gene screening