Very oddly compelling. I can't think of very many good procedurals which also have supernatural setups -- Kate Wilhelm's Death Qualified is another (I'm sure there are more, that's just one of the few I can think of right now). Very satisfying in that first-five-minutes-of-Prime-Suspect way in which everything's happening and you can't figure it out and it all isn't neatly explained, so it stretches your brain a bit. Originally published in 1971 and some of the gender issues are very dated -- a scientist will "never" marry a young heiress because of her genetic background (can't they not have kids? adopt?), many nurses are pinched, women are automatically and bluntly rated on an attractiveness scale when they first enter the narrative, and so on. But the female characters themselves were quite good -- I liked the spoiled Doll, the comically gruesome Lady Sospice, and "poor Posey" very much. The book really isn't about genetics or telepathy or corruption or crime at all, although Dickinson weaves all these themes into his central, real one: obsession. The children are like little fleshy rings of Gyges: what they are matters less than what other people do with them. And the book itself is almost hypnotically gripping....like the sleepy children themselves, eerily alluring. Dickinson makes even the tremendously stale copper-confronts-the-sympathetic-bad-guy endpiece (which actually happens twice) interesting -- it's a dangerous skill, like a knife: bright but with an edge.
What do You think about Sleep And His Brother (1986)?