Genetic testing

In genetic testing, a blood sample is taken and sent to a laboratory where the DNA of the person is examined. DNA is the carrier of genetic information.

Click here to watch a short film on finding genetic changes that cause disease

In medical terminology, both genetic and inherited mean the same thing; the condition has developed from your genetic makeup.  Genetic testing may also be referred to as genotyping.

In inherited sight loss conditions there is a genetic fault in one gene (which is commonly described as a mutation) and the genetic testing will seek this gene to give a firm diagnosis of the specific condition.

Why undertake genetic testing?

It can be helpful to know the exact fault carried in the genes as it can assist in prediction of how vision may change in the future, and also help to determine the likelihood of other family members developing the condition. In addition, many of the treatments currently being developed are specific to certain genetic faults, so knowing your genetic diagnosis will potentially open up choices about clinical trial participation and future treatment options.

For genetic testing, you should ask to be referred to regional eye genetic clinics which are run by a combination of ophthalmologists and geneticists who can then arrange for genetic testing to be done.

The availability of genetic testing does vary across the UK and may not be offered routinely. If you are not offered genetic testing at the time of your initial diagnosis, ask if it something that is available.

Information on this page is based on that kindly provided by Professor Graeme Black at Manchester Eye Hospital. Video animation used with kind permission of Dr Mariya Moosajee and Meike Walcha-Lu, film-maker for the NIHR Moorfields.