My husband’s brother had muscular dystrophy

I’ve never had the pleasure of meeting my hubby’s brother, but I’ve heard great things. 😢He was diagnosed with MD around 4 years old and was put in a wheelchair probably around 9-10 years old. I was told he was the first and only person in the family to have MD. He actually ended up passing away from the disease when he was 27 years old. I wish I could’ve met him. 😭😭😭

Before we started trying to get pregnant I met with a genetic counselor and was told that MD was only transferred to the child from the X chromosome (the mother) so I shouldn’t have anything to worry about. The only thing that troubles me is that my mother in law said she did get all of these tests done and she told me she’s not the one who carried the gene...so now I’m confused. I had some sort of test done at my first OB appointment to check for MD and I’m impatiently waiting for the results. Has anyone here ever had an experience with MD in the family and pregnancy? Any stories would be helpful.