It is said that about 25 percent of human life span is controlled by genetic factors. Other factors that play a role in longevity are environment and lifestyle. Over the years, better environmental conditions in terms of clean and proper housing, nutritious food, potable water supply, and access to better medical care, has increased the average life span of humans.

What does it mean if a disorder seems to ‘run in my family’?
When a disorder has affected more than one


