Researchers at Imperial College London (ICL) are reporting success of a preliminary pilot study of the SNP DR device.
Pronounced as “Snip doctor”, the handheld tool developed by ICL spinoff company DNA Electronics identifies markers for reactions to prescription medications by spotting single nucleotide polymorphisms within the DNA on a saliva sample.
The SNP DR works by analysing the DNA in saliva samples, which are placed in a disposable cartridge and exposed to silicon chip sensors inside the device. Copies of SNPs are contained in the chip. If the device detects a match, a message is displayed on the SNP DR’s handheld console. The SNP DR will allow physicians to assess their patient in the GP clinic and tailor dosages and treatments accordingly, rather than sending samples to a laboratory for analysis, which is a costly and lengthy process that can delay therapies. At present, the real-time SNP Dr takes approximately 30 minutes to analyse a sample.
Researchers from DNAE collaborated with Imperial College London and the pharmaceutical company Pfizer to develop and test the SNP DR detection module under a £1.2M project part-funded by the UK government’s Technology Strategy Board, which began in 2008. Pfizer researchers supplied 26 DNA samples that had been analysed in a laboratory to determine their genetic make-up, providing the reference against which the DNAE team could compare their SNP DR results to. Because this was a blinded trial, the DNAE researchers did not know the results of the test performed on Pfizer’s samples until after they had completed the study.
In the pilot study, the team configured the device so that it could detect the CYP2C9*2 and CYP2C9*3 SNPs in the samples supplied by Pfizer. These SNPs indicate how people metabolise 20% of therapeutic drugs. The DNAE team used the SNP DR to determine which samples contained these SNPs and then compared the SNP DR data with the data from Pfizer. They correctly called a 100 percent of a small subset of the samples tested blindly.
The next stage will see the team further refining the technology so that more SNPs could be analysed by the SNP Dr at once. This would mean that SNP DR could detect more complex reactions to drugs. It could also enable the device to detect a range of diseases and bacterial infections in the GP surgery, by quickly testing a sample of someone’s DNA.
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