Long before birth, females permanently turn off one copy of their X chromosome in each cell, so that like males they operate with just one copy functioning. But scientists have long known that inactivation isn't perfect. Some genes on the inactivated copy continue to function, sending out chemical orders for the cell to manufacture specific proteins.

So, is it possible that certain genes can't be that easily silenced? Is there some genetic traits from either parent that continue to provide influence into their offspring even where the other parents genes in that area are dominant?

X Chromosome Key to Differences in Men and Women | LiveScience