Inherited sight loss conditions are caused by ‘faults’ in the genes (instructions) in the cells of our body that are required to build and maintain the health of the retina.
A fault in a gene is sometimes described as a ‘spelling mistake’ in the DNA code (or ‘mutation’). We inherit our genes from our parents in the form of sperm and egg. All our genes come in pairs and when we pass our genes on to our children, we pass on just one copy. The child inherits one copy from their mother and one copy from their father.
Genetic conditions can be passed on from one generation to the next in a variety of ways. These are called the patterns of inheritance. In the eye clinic, your doctor or genetic counsellor will spend some time asking about other people in your family to try to work out the pattern of inheritance. In some families a condition may have been present for several generations but in others there may be no other person known to be affected.
There are three ways in which inherited sight loss conditions can be inherited or passed on: