So some clusters of cells express the maternal X chromosome, while others express the paternal X.

所以一些细胞簇表达母系 X 染色体，而另一些则表达父系 X 染色体。

But one thing to be aware of, is that a mutation to the same region of genes on the maternal chromosome can affect a gene called UBE3A, which is only expressed on the maternal chromosome and imprinted on the paternal.

但需要注意，母源染色体相同区域的基因突变会影响UBE3A基因，此基因仅在母源染色体上表达，在父源染色体上发生印记被沉默。