Genetic family tree is a schematic family tree that shows the biological inheritance of some trait through successive generations.
Genetic family trees are useful because it is practically impossible and ethically unacceptable to make experimental crossings for genetic testing between human beings. With the help of family tress the study is made by analysis of marriages (and crossings) that have already occurred in the past. From the analysis of family trees, for example, information on probabilities of the emergence of some phenotype and genotypes (including genetic diseases) in the offspring of a couple can be obtained.