Myotonic Dystrophy

A 31-year-old gentleman presented with gait imbalance since childhood. He was unable to run in school sports and playground and used to fall recurrently. Gradually he started developing difficulty in walking. He was lethargic and had subnormal intelligence in academics. He also had difficulty in gripping objects, mild slurring of speech, low appetite, and recurrent pain and swelling of legs (left > right). He has three maternal uncles who have similar problems. His mother died at the age of 50 years; she was bedridden and had loss of speech during last few years of her life. One of his brothers was also affected with similar problem who died because of head injury.