目前,世界上已发现近三千多种遗传病。为了预防出生有遗传缺陷的孩子,未婚和已婚的男女,都应该懂得一点遗传的知识。什么是遗传病呢?遗传病是指遗传物质、基因或染色体发生了改变而造成的疾病。遗传病的发生需要一定的遗化因素,按一定的方式在上下代之间垂直传递,缺少这种遗传因素就不会发病。因此,发病表现 At present, nearly 3000 kinds of genetic diseases have been found in the world. To prevent the birth of a child with genetic defects, both unmarried and married men and women should know a little genetic knowledge. What is a genetic disease? Genetic disease refers to genetic material, genetic or chromosomal changes caused by the disease. The occurrence of genetic disease requires a certain degree of genetic factors, according to a certain way vertical transmission between the next generation, lack of such genetic factors will not be the disease. Therefore, the performance of the disease