If a woman inactivates her good X and has a disease caused by a mutation on her other X, does that mean that all her daughters who inherit the mutated X will also get the disease?
No. The X chromosomes in her gametes are both capable of being the active X after fertilization. Each daughter will have a 50% risk of inheriting the mutated X. She will also inherit a healthy X from her father. The two X’s will then inactivate randomly and the daughter will usually have a healthy phenotype.
