Bioethicists teaching and writing about the uses of prenatal genetic testing sometimes use "difficult cases" in which people with a disability want to test and select for the presence of their disability. Such cases challenge our stereotypes but also play into them.
The ethics of teaching genetic dilemmas
Gooding, H. C., Wilfond, B., Boehm, K., & Biesecker, B. B. (2002). Unintended messages: The ethics of teaching genetic dilemmas. Hastings Center Report, 32(2), 37-9.