遗传的生理缺陷，只能用“命”来解释了。

有一种基因缺陷导致的病叫cystic fibrosis。

Cystic fibrosis (CF) is a genetic (inherited) disease that causes sticky, thick mucus to build up in organs, including the lungs and the pancreas. In people who have CF, thick mucus clogs the airways and makes it difficult to breathe. Management includes ways of clearing lungs and eating correctly.

天生的气管和胰脏导管分泌过多粘液，堵气管赌胰脏，由此产生各种并发症。医疗条件好的话，能活到四十六岁。