I wouldn't say that you are likely to have the gene - you will only have a chance of carrying the gene if one of your parents does. So in this case if your mother carries the gene then you may too, but not necessarily. Does your mother know if she carries the gene?

If you are carrying the gene then you may be able to have embryo screening if you wish and if it is available for this particular gene. Alternatively you may be able to do pre-implantation sex selection and choose to only have girls (although they may still be carriers unless you combine this will gene selection). Of course all these will be time consuming and there will be costs involved which I'm sure you are aware of. In the end you and DH need to make a decision on the potential risks for your children and do what you feel comfortable with.

I'm sorry about your uncle, I know somebody with MD and it is just awful. There is quite a lot of research being done on MD, in particular with stem cells. Lets hope that in the future it will be treatable!