Pernicious anemia is a rare blood disorder characterized by the inability of the body to properly utilize vitamin B12, which is essential for the development of red blood cells. Most cases result from the lack of the gastric protein known as intrinsic factor, without which vitamin B12 cannot be absorbed.
The symptoms of pernicious anemia may include weakness, fatigue, an upset stomach, an abnormally rapid heartbeat (tachycardia), and/or chest pains. Recurring episodes of anemia (megaloblastic) and an abnormal yellow coloration of the skin (jaundice) are also common. Pernicious anemia is thought to be an autoimmune disorder, and certain people may have a genetic predisposition to this disorder.
There is a rare congenital form of pernicious anemia in which babies are born lacking the ability to produce effective intrinsic factor. There is also a juvenile form of the disease, but pernicious anemia typically does not appear before the age of 30. The onset of the disease is slow and may span decades. When the disease goes undiagnosed and untreated for a long period of time, it may lead to neurological complications. Nerve cells and blood cells need vitamin B12 to function properly.
