3.Women with one mutated gene copy have a remaining healthy copy, so they don't get hemophilia unless X-chromosome inactivation turns off the normal copy in the majority of cells.
4.There are still unresolved questions about X inactivation, like how some genes on the X chromosome escape inactivation and why inactivation isn't always random.
关于 X 失活仍有未解决的问题,例如 X 染色体上的些基因如何逃脱失活以及为什么失活并总是随机的。机翻
5.Now if this inactivation's random, you'd expect about half of the female's cells to have a functional dystrophin gene and the other half to have a defective dystrophin gene, and these people are typically asymptomatic.