Comment by Pawamoy

This is probably a bit off-topic, but I wonder if you know about the GenIDA project: https://genida.unistra.fr/. It's basically a research website where families can register and answer questionnaires about the everyday life of patients with rare diseases. The data can then be used to discover new things about these rare diseases. They have a Kleefstra cohort if I recall correctly. Maybe you could get in touch with the people in charge, like Jean-Louis Mandel.