acromegaly and gigantism: in a nut shell...?

Question

physiological cause?
social strategies/behavioral recommendations for patients and families?

Answer 1

both are caused by exess growth hormone. If this excess is during child hood then you get gigantism. If it happens after growth plates have fused you get acromegaly.

http://www.emedicine.com/med/topic27.htm
http://www.nlm.nih.gov/medlineplus/ency/article/001174.htm

Answer 2

Too much Growth Hormone (given out by pituitary gland), both conditions.

This article gives a good summary of acromegaly.