1.Genetics -the study of heredity and the variation of inherited characteristics.

2.Environmental -relating to the natural world and the impact of human activity on its condition.

3. Lifestyle choices -a choice a person makes about how to live and behave, according to their attitudes, tastes, and values.

                                  Charcot–Marie–Tooth disease

1. peroneal muscular atrophy  comprises a group of disorders that affect peripheral nerves.

2.The neuropathy of CMT affects both motor and sensory nerves. motor nerves cause muscles to contract and control voluntary muscle activity such as speaking walking breathing  and swallowing.

3.A nerve cell communicates information to distant targets by sending electrical signals down a long  thin part of the cell called the axon.

4.Diagnosis of CMT begins with a standard medical history family history and neurological examination.

5.There is no cure for CMT  but physical therapy, occupational therapy  braces and other orthopedic devices and even orthopedic surgery can help individuals cope with the disabling symptoms of the disease.

1.is the most common type of heart disease. It is the leading cause of death in the United States in both men and women.

2.happens when the arteries that supply blood to heart muscle become hardened and narrowed.

3.This buildup is called atherosclerosis . As it grows  less blood can flow through the arteries.

4.cuts off the hearts blood supply  causing permanent heart damage.

1.a form of brain disease.

2.No one knows the exact cause but a real breakdown of the cells of the brain does occur.

3.There is no treatment  but good nutrition may slow the progress of this lifestyle disease  which lasts about seven years in most people who have it.