This study has identified the anterior cingulate cortex (ACC) as a key area in the brain responsible for sensory hypersensitivity in autism spectrum disorders. Utilizing a mouse model with a Grin2b gene mutation, heightened neural activity and connectivity in the ACC was observed. Suppressing this hyperactivity normalized the sensory hypersensitivity, offering new insights into treatment options
https://www.nature.com/articles/s41380-024-02572-y (open access)
This isn’t quite true. Physical medicine also has many diseases that are just grouped together symptoms with unknown etiology. They are referred to as syndromes: https://en.m.wikipedia.org/wiki/Syndrome