Shortly after my daughter's diagnosis, my wife and I also underwent genetic testing to ensure that there weren't any aspects of our makeup that are conducive to 1p36 deletions. The results showed that nothing in my genes or my wife's lead to our daughters disorder. That's where we left things until this summer.
My wife and I have talked quite a bit about the benefit that my little one could derive from having a sibling to observe and learn from. Before my daughter, we had planned to have our children about three years apart. But this became a huge source for discussion because my daughter is far from self-sufficient and an additional child would greatly increase the workload around our home. We were worried about another child taking away from the amount of time we're able to focus on our daughter's care and progress. We really went back and forth on this for quite a while.
In the end we decided it was time. My little girl will have a littler brother or sister coming in April. While my wife and I are very excited about this development, but there are still concerns. The "what if"s creep in and sometimes we're left wondering how things will turn out. How would we deal with raising two disabled children? I will welcome any new little one into our family regardless of health concerns or other circumstances. But I hope never to answer that question.