How to know if there is genetic compatibility between a couple or with the donor?

We talk about genetic compatibility when we analyse the risk of two people having a child with one of the diseases analysed. 

To do this, both must carry out a genetic study of carriers, in which possible genetic mutations will be detected. Generally, these genetic mutations do not usually have clinical relevance because they are usually recessive.

With these results, the two can be compared in order to establish a risk of the future child having one of these diseases.