I read this book in a closet at a resort during spring break '93, when I was 10 years old. I was going through a mild (and secretive because I thought I had to hide it) John Grisham obsession, and I think my mom may have suggested this... or maybe I just took it from her after she read it. I ended up loving this book, and spent years afterwards looking for it again but never found it. Now, nearly 30 years later, I came across it and even though I'm fairly certain I'll never read this again because my reading tastes have changed over the years, but it's been driving me insane for so long trying to find it that I had to at least bookmark it here. I thought Sophie was so cool, and at times even now kind of wish I had developed her mental prowess.
This book probably wasn't "appropriate" for me at 10, in terms of adult content, but it had a fascinating premise ("designer DNA" babies), a cool kid with powers as one of the MC's, and because it was written "for adults" it didn't dumb things down to a level adults THINK speaks to kids. I'll say it a million times, I wish YA was an actual thing when I was a kid, and the people responsible today for getting those books out into the world are heroes.