My family doesn't have many, if any, genetic disorders, but many mental diseases have been passed down through the generations. The gene of having schizophrenia, bipolar disorder, et cetera have been passed down on one side of my family into every generation, and, for that reason, I could assume that it's a dominant trait. Other things like cancer, diabetes, heart disease, and just an over all weak immune system are infamous for appearing in many of the generations in my family. I am grateful of the fact that, as far as I know, no one has received sickle cell, Down syndrome, hemophilia, cystic fibrosis, and such.
In the future of genetics, I hope we are able to more accurately spot and eliminate diseases that have bad potential for our lives. Maybe we could replace things that'll have a bad effect with healthy genes, but still be a result of our parents. This would require heavy advancements from where we are to day and many decades of strenuous work, of course. Maybe this is where 3D printers could come into play, when, if ever, they are able to create individual DNA.