And this is what happens in Prader-Willi syndrome!

这也就导致了普拉德-威利综合征的产生。

Usually, newborns with Prader-Willi syndrome have low muscle tone making them extremely floppy.

普拉德-威利综合征的新生儿常伴随肌张力低下，肌肉非常松弛。

Now, with Prader-Willi syndrome, there's a mutation in the Prader-Willi gene region on the paternal chromosome.

现在我们已经知道，在普拉德-威利综合征中，父源染色体区域发生突变。

Alright, as a quick recap, Prader-Willi syndrome is an imprinting disorder, where mutations on only the paternal copy of a chromosome causes the disease.

好，快速回顾一下：普拉德-威利综合征是一种印记病，仅在父源染色体突变时发生。

A third way to get Prader-Willi syndrome, is a mutation in the imprinting center, which is a sequence of DNA near the Prader-Willi genes that directs imprinting via sex-specific methylation.

第三种导致普拉德-威利综合征的原因是印记中心的突变；印记中心是临近普拉德-威利基因的DNA序列，通过性别特异的甲基化介导印记。