Mara Tagarelli, the main character in So Lucky by Nicola Griffith, has multiple sclerosis.
From the publisher:
Mara Tagarelli is on top of her world. She’s the head of a multimillion-dollar AIDS foundation, an accomplished martial artist, and happily married. Then, in the space of a week, her wife leaves her, she is diagnosed with multiple sclerosis, and she loses her job.
US publisher: MCD x FSG Originals (May, 2018)
UK publisher: Handheld Press (November, 2018)
Author represented by: Stephanie Cabot of The Gernert Company