The term ‘myopathy’ is missing from Vikivortaro, ReVo, Sonja, Vikipedio, and Wells. It is also missing from Benson, but Benson at least includes the prefix ‘mi(o)-’ referring to ‘muscle’. I combined that with a ‘patio’ (a shorted form of ‘patologio’) to get ‘miopatio’ as the translation of ‘myopathy’ that I used in translation my excerpt from the Wikipedia obituary on Pierre Bergé.

http://vortaro.net/#kardimiopatio