multiple sclerosis (ms) is the most common chronic neurological disease in adults of 20 the 50 years, and with a number of symptoms manifested by the gradual accumulation of disability.

How would the previous sentence be correctly capitalized?
Multiple sclerosis (MS) is the most common chronic neurological disease in adults of 20 the 50 years, and with a number of symptoms manifested by the gradual accumulation of disability.