<prompt> Bilateral ptosis is not seen in:Marfans syndromeMyaesthenia gravisMyotonic dystrophyKearns sayre syndrome  <response>: Ptosis does not occur in Marfans syndrome. Ref: Management of Genetic Syndrome By Suzanne B, 3rd Edition, Page 509 ; Clinical Ophthalmology By Kanski, 3rd Edition, Page 493 and 4th Edition, Page 180-1, 376-77 3. Comprehensive Ophthalmology By A K Khurana, 4th Edition, Page 202 