Women and Synesthesia

from: Synesthesia- Synesthesia for Kids

I found it interesting that the majority of synesthetes are women and it appears to run in families. The article mentions that this is a dominant gene but it does not say what chromosome it is linked to. Since it appears to be more common in women, I wonder if it is linked to the X chromosome. Since women have two X chromosomes, they would be twice as likely to inherit the synesthesia gene then men who only have one x chromosome, which could explain why it is more often found in women. It is not a recessive gene, so they only need one copy of it to have synesthesia. It must be hard find how many people have synesthesia since so many of them who have it don't know that they do.