If having a gene for any illness condemns you to having that disease, then why are you not born with the disease you are coded to have?

如果是疾病的基因导致你也有这个疾病，那为什么你生下来时没有这种疾病？

youdao

A child who inherits two of the same trait genes - one from each parent - will be born with the disease.

子女若继承了两个相同的特征基因(分别来自父母)，生下来即患有该疾病。

youdao

He was a writer who worked hard for $150 a week. He never whined or complained about money or that he was born with a painful disease called sickle cell.

他写作为生，为了每周150美元的收入辛勤工作，但他从不抱怨钱的问题，也没有因为生来就患有镰刀细胞病——一种伴随着巨大的疼痛的疾病——而自怨自艾。

youdao

Zhang,and his younger brother Haiyang, were born in China, one of several Asian countries where the disease is endemic.

VOA: standard.2010.07.26

Wheat Stem Rust is a devastating wind-born disease affecting cereals that has spread across Africa and is now in the Middle East, and migrating further eastwards.

CNN: Feeding the future: Saving agricultural biodiversity

There are other children born with disease and disability, like cystic fibrosis or juvenile diabetes.

FORBES: Yes, Health Care is a Right -- An Individual Right

He died before I was born of lung disease due to the mustard gas.

BBC: NEWS | Have Your Say | WWI ceremony: Your thoughts