But just as there are ordinary good-enough parents who mysteriously produce a difficult child, there are some decent people who have the misfortune of having a truly toxic parent.

但是正如有一些普通足够好的父母不可思议地制造出一个难以相处的孩子。一些大方得体的人们很不幸地有让人无法忍受的父母。

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Even if there was, there is thought to be only a one in 50 chance of the Whittakers having another child with the illness, so they would not be good candidates for this type of "pre-implantation genetic diagnosis".

BBC: Q&A: 'Designer baby' refusal