François J
Klin Monbl Augenheilkd. 1981 Aug;179(2):71-7.
What is the empirical risk of children being born with a disease or malformation? In healthy families, the parents being normal, the probability is 2 to 4%; when the parents are first cousins, although healthy, it is 5%. Of course, the risk if greater in affected families. When the mother or father is affected and there is no consanguinity, the risk if 20%, but when the parents are first cousins, it is 32.5%. When both parents are affected it is 100%. When the parents are normal but one child is affected, the risk for the other children is 25%. When the mother or father is affected and there is already one child affected, the risk for the other children is 50%. When a grandparent is affected, the risk for the grandchildren is 10%. When an aunt or an uncle is affected, the risk for the nephews and nieces is 7%. With regard to genetic counseling, the parents must understand that no physician can guarantee that a child will be normal. They must also understand that the mendelian risks are the same for each pregnancy. Finally, they must know that for each child there is a 2 to 4% risk of a major congenital anomaly. From the human and psychological point of view, the physician must convince the parents that they are not responsible and that both the husband and the wife may carry pathologic genes, as every individual carries 2 to 10 pathologically recessive genes. Finally, it is not the geneticist's responsibility to impose a decision. Only the parents can decide whether they want more children or not.
孩子出生时患有疾病或畸形的经验性风险是多少？在健康家庭中，父母正常，其概率为2%至4%；当父母是近亲时，尽管他们健康，但概率为5%。当然，在患病家庭中风险更高。当母亲或父亲患病且无血缘关系时，风险为20%，但当父母是近亲时，风险为32.5%。当父母双方都患病时，风险为100%。当父母正常但一个孩子患病时，其他孩子的风险为25%。当母亲或父亲患病且已有一个孩子患病时，其他孩子的风险为50%。当祖父母患病时，孙辈的风险为10%。当姑姑或叔叔患病时，侄子侄女的风险为7%。关于遗传咨询，父母必须明白，没有医生能保证孩子会正常。他们还必须明白，孟德尔风险对每次怀孕都是相同的。最后，他们必须知道，每个孩子都有2%至4%的风险患重大先天性异常。从人文和心理角度来看，医生必须让父母相信他们没有责任，而且丈夫和妻子都可能携带病理基因，因为每个人都携带2至10个病理性隐性基因。最后，做出决定不是遗传学家的责任。只有父母才能决定他们是否想要更多孩子。
