Consanguineous marriage is the marriage between partners having kinship to each other. Primary consanguineous marriage is defined as a union between two individuals who are related as cousins or closer. In Turkey, the ratio for consanguineous marriage is between %21 and % 40 and it varies from region to region. This is the highest rate of consanguineous marriage in the World except for few highly isolated populations.

Every 2-3 (2%) children out of 100 are born with certain anomalies due to different reasons within the society. This risk doubles in consanguineous marriages. Therefore, in these families, pregnancies should be regularly monitored and a second level of ultrasonography must certainly be applied to. For the newborns, screening tests should be performed for highly observed recessive inherited diseases such as phenylketonuria. These couples should be warned to wait 1-2 years for the next pregnancy since some findings of certain recessive diseases may emerge at the early periods of development.

Consanguineous marriage has a higher potential for transmission of the same mutant gene, it increases the chance of transmission for rarely observed autosomal recessive diseases if an autosomal recessive disease exists due to consanguineous marriage, the probability of having a sick child is 25% per delivery.