So-called recessively inherited disorders, such as Tay-Sachs disease, cystic fibrosis and red blood cell disorders known as thalessemias are rare. 所谓隐性遗传疾病,像“泰-萨克斯病”、“囊性纤维化”,以及被称为“地中海贫血症”的血细胞疾病,都很罕见。
PGD is good for screening for specific genetic disorders such as cystic fibrosis and Tay-Sachs disease, and also can be used to select gender. PGD适用于特殊遗传病的筛查,如囊性纤维化和神经节苷脂病,而且PGD也可以用于性别选择。
Tay-Sachs is most common among Askenazi Jews and French Canadian populations, while cystic fibrosis is mostly seen in people of Northern European descent. “泰-萨克斯病”在德系犹太人和法裔加拿大人中最常见。而“囊性纤维化”疾病常见于北欧后裔中。
The sphingolipid-storage diseases, Tay-Sachs, Gaucher's and Niemann-Pick, all involve extra growth and branching of the protuberances that connect nerve cells together. 鞘脂储存类疾病,如泰萨二氏病、脑苷脂沉积病和神经鞘磷脂沉积病,都涉及到连接神经细胞的凸起的多余生长和分叉。
These enlarged, pale neurons are in a baby with Tay-Sachs disease, which is seen mostly in persons of European Jewish heritage. Sachs病的婴儿会出现扩大的苍白色神经元,这在欧洲犹太后裔最常见。
But increased intelligence may have come at a cost, with genetic disease such as Tay-Sachs being side effects of genes that facilitate intelligence. 然而智商的增长是有代价的,提高智商的副作用就是导致家族性黑蒙白痴症等这样的遗传病。