You need only one mutated gene to be affected by this type of disorder. In an autosomal dominant disorder, the mutated gene is a dominant gene located on one of the nonsex chromosomes (autosomes). It isn't clear what causes essential tremor in people without a known genetic mutation. This form is referred to as familial tremor. Parkinson's disease tremors usually start in your hands, and can affect your legs, chin and other parts of your body.ДЄbout half of essential tremor cases appear to result from a genetic mutation. Essential tremor mainly involves your hands, head and voice. However, people with essential tremor sometimes develop other neurological signs and symptoms, such as an unsteady gait (ataxia). Essential tremor doesn't cause other health problems, but Parkinson's disease is associated with stooped posture, slow movement and shuffling gait. Tremors from Parkinson's disease are most prominent when your hands are at your sides or resting in your lap. Essential tremor of the hands usually occurs when you use your hands. Many people associate tremors with Parkinson's disease, but the two conditions differ in key ways: May be aggravated by emotional stress, fatigue, caffeine or temperature extremes.Can include a 'yes-yes' or 'no-no' motion of the head.Usually occur in the hands first, affecting one hand or both hands.Begin gradually, usually more prominently on one side of the body.

Why is my body shaking for no reason