DNA testing in eye care practice

Most readers will have heard the recent news stories about DNA testing kits becoming more widely available. A number of kits have been introduced whereby a swab is taken from the inside of the mouth. The saliva and lining remnants are then sent to a lab where the sample is analysed. Variations in the base sequence are known as single nucleotide polymorphisms (SNPs) and the density of SNPs is used as an indicator of disease risk. The nature of the disease will be dictated by the nature and position (within specific genes or ‘stretches’ of the DNA) of the SNP.

Five tests have been developed in the US and have been used to indicate the risk of developing age-related macular degeneration. It was one of these, the 23andMe test, that was responsible for much of the recent publicity because, having been banned (by the FDA) from sale to the public in the US, it has been launched onto the market in the UK.