A gene mutation is a permanent alteration in the DNA sequence that makes up a gene, such that the sequence differs from what is found in most people.Mutations range in size; they can affect anywhere from a single DNA building block (base pair) to a large segment of a chromosome that includes multiple genes. gene mutation is a permanent alteration in the DNA sequence that makes up a gene, such that the sequence differs from what is found in most people.
True labor contractions last more than 30 seconds at the onset and get progressively longer, up to 60 seconds, whereas false labor contractions vary in length and intensity.
Unlike a sudden contraction in an arm muscle, though, a contraction in your heart muscle can have very serious results very quickly. A coronary artery spasm might last anywhere from five to 30 minutes, and it can cause chest pain [source: MedLine Plus ]. Chest pain is usually called angina.