I am concerned about my nephew. He is 18 years old an, but developmentally seems to be around age 13. He is very large for his age... He is 6 ft 7 inches tall, and weighs 367 pounds. He is a delightful kid, but struggles to learn. In some areas such as music,He is far beyond his peers( brilliant). He often complains of body aches and fatigue. .. He has always been clumsy, both physically,and socially. He was offered a scholarship in music, but has not been able to pass his GED. He had trouble breathing at birth... Any thoughts?