My daughter wants to abort after genetic testing - need advice

I (53M) am struggling with a situation involving my daughter (28F) and her husband (30M). They're expecting their first child, and my daughter has always been excited about becoming a mom. I was thrilled when she told me about the pregnancy.

Recently, they got genetic testing done and my daughter told me the results showed the baby might have Parkinson's disease. She said they've decided to terminate the pregnancy because of this. I don't know the exact odds or how certain the test results are, but she made it sound like there was a real possibility.

Here's where I'm conflicted: I genuinely believe that people with Parkinson's can live long, meaningful lives, especially with today's treatments and support systems. I've seen people manage this condition for decades while maintaining good quality of life. I tried to express this to her, explaining that a Parkinson's diagnosis doesn't mean the child couldn't have a fulfilling life.

I also brought up her cousin (my niece), who was told years ago that her baby might have Down syndrome. The doctors were wrong - the baby was born completely healthy. I thought this family example might help show that these tests aren't always definitive and that there's hope even with concerning results.

My daughter didn't take this well at all. She got very upset, saying I was judging her decision and not respecting her feelings. Her husband backed her up, telling me I was out of line for bringing up her cousin's situation. They said it's their choice alone and that I don't understand what they're going through.

Now they've completely cut contact with me - no calls, texts, and I'm not welcome at their home. It's been weeks, and I'm heartbroken. I love my daughter deeply and was so excited to be a grandfather.

I'm torn because I understand it's ultimately their decision, but I can't shake the feeling that they might be making a choice they'll regret later, especially since people with Parkinson's can live long lives. Should I have kept my opinions to myself? Should I have shared my perspective and our family's experience? How do I repair this relationship while staying true to my beliefs?

Any advice would be appreciated. I just want my daughter back in my life.