Marriage between Cousins will increase the incidence of genetic diseases in offspring, the early mortality and deformity rate of offspring are also relatively high, and there will be poor physical fitness and shorter height. Secondly, China's law clearly stipulates that close relatives can not marry, if the fact is concealed to register, then the relevant authorities have the right to cancel the marriage.
1. Annulment of marriage
According to the current law of China, there is no specific legal punishment for marriage of close relatives, but the marriage of close relatives, the registration authority is not allowed to register marriage, if the fact is concealed for registration, then the marriage is a factor of invalid marriage, marriage registration authority or the court has the right to revoke the marriage. One of the circumstances under which marriage is explicitly prohibited by our law is the prohibition of marriage between immediate relatives and collateral relatives within three generations.
2. Increased incidence of genetic diseases in offspring
Due to the existence of blood relations between close relatives, there are similar genetic factors, inbreeding, which increases the risk of certain autosomal 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.