is best defined as a sudden variation in an inheritable characteristic, as distinguished from a variation that results from generations of gradual selection.

Mutation

Explanation: Mutation is a change in DNA sequence, it may occur due to error when the DNA is copied or it can arise from various environmental factors such as exposure to chemicals, UV radiation, Highly infectious microbes.

Mutation maybe spontaneous. Acquired mutations occur at some point in a person's life and are present only in certain cells, not in every cell in the body while some may target a tissue, an organ or an entire system.

you know that this symptom is misleading and quite often is related to: heart attack

a heart attack is a condition that occurs when the blood flow that transports oxygen to the heart muscle is damaged or cut off completely. the coronary arteries that supply the heart muscle with blood flow can be blocked by the accumulation of plaque. also, when the plaque within the heart artery breaks, it creates blood clot that can also hinder the blood flow. men that are over 45years of age and women that are over 55years of age are at risk of having a heart attack. the symptoms of a heart attack include chest discomfort, chest pain, coughing, and shortness of breath.