Genetic counselling is done by specially trained doctors who can often predict what the risks are of couples passing on an inherited disease to their children. This risk may be high, moderate or very low. This assessment can be done before a couple decides to conceive - or even before a couple makes a decision to get married. Sometimes the assessment involves having tests to find out if either partner is carrying the gene for a particular disorder. Our bodies carry thousands of genes which are like plans that decide how a person is going to look and function.
Some genes determine the colour of our eyes, for example, and the shape of our nose.
Although this doesn't happen often, it's more likely to happen when someone marries a relative such as a cousin. Among cousins who intermarry, there's a higher risk of having miscarriages or producing babies with a number of disorders causing physical disabilities, malformations and mental retardation. Some of these babies die shortly after birth. This is why it can be a good idea for cousins to seek genetic counselling before deciding to marry. Because there can be good social reasons for people to marry within the family, it can be hard for a couple to know what to do if they learn they have a high risk of passing on an inherited disease.