If a particular woman is a carrier (XhXH) for a sex-linked disease that means she has one copy of the recessive gene on X-chromosome(Xh) and one copy of the dominant gene on X- chromosome (XH).
For a male offspring of a carrier mother to not get affected by a sex-linked disorder there are 50 percent chances if his father is not affected. In this case, Male offspring receive an X chromosome only from mother. So it could be Xh or XH so this offspring has a 50% chance of being affected or unaffected.
