Consanguineous marriage will have a certain effect on grandchildren. The offspring of consanguineous marriage have a high mortality rate, and often appear dementia, teratoma and genetic disease patients. This is because couples who marry close relatives get more of the same genes from a common ancestor, which is easy to make recessive harmful genes that are unfavorable to survival meet in the offspring (that is, homozygous), and thus easy to birth poor quality children.
Early mortality and malformation rates are higher in children born to close relatives. The offspring of consineous marriages will have poorer physical health, lower weight and shorter height. The probability of developing genetic diseases in the grandchildren's generation is also significantly higher than that of non-close relatives. People know from countless facts that the marriage of men and women who are close to each other has a high mortality rate, and often dementia, deformities and genetic diseases. This is because couples who marry close relatives get more of the same genes from a common ancestor.
Consanguineous marriage will greatly increase the probability of recessive genetic diseases. The recessive genetic disease in the offspring of inbred marriage will be 150 times more than that in the offspring of non-inbred marriage. According to the survey, the incidence of polygenic diseases such as congenital heart disease, anencephaly, and spinal cord fission in the offspring of consanguineous marriages is about 1.64%, which is higher than that of non-consanguineous children. Hypertension, schizophrenia, epilepsy and other polygenic genetic diseases, the incidence of children born of consanguineous marriage is significantly higher than that of non-consanguineous marriage.