What is the difference between Acromegaly and Gigantism?

Giantism is the result if the disease mechanism starts in childhood, whereas acromegaly is the result if the disease mechanism begins after puberty. Acromegaly is more common than giantism. Giantism is so rare that there are only about a hundred known cases of it recorded. Mortality rates of giantism during childhood are unknown because the disease is so rare and unusual.

The mortality rate of those with acromegaly is two to three times that of the general population. Giantism begins at any age before puberty, whereas acromegaly occurs at around the third decade. Giantism features excessive tallness while acromegaly features excessive growth of the lower jaw, tongue, and finger ends.