Aplastic anemia occurs when blood-forming stem cells in bone marrow can't produce enough red blood cells, white blood cells or platelets. The cells that are made are normal. Sometimes there's a genetic cause that was passed from parent to child, but most often it results from the accidental destruction of stem cells by the immune system.
Acquired Aplastic Anemia
Acquired aplastic anemia is usually considered an autoimmune disease. Normally, your immune system attacks only foreign substances. When your immune system attacks your own body, you are said to have an autoimmune disease. Other autoimmune diseases include rheumatoid arthritis and lupus.
Acquired aplastic anemia can begin at any time in life. About 75 out of 100 cases of acquired aplastic anemia are idiopathic. This means they have no known cause. In the remaining cases, the cause can often be linked to:
- Toxins, such as pesticides, arsenic and benzene
- Radiation and chemotherapy used to treat cancer
- Treatments for other autoimmune diseases, such as rheumatoid arthritis and lupus
- Pregnancy - sometimes, this type of aplastic anemia improves on its own after the woman gives birth
- Infectious diseases, such as hepatitis, Epstein-Barr virus, cytomegalovirus (si-to-MEG-ah-lo-VI-rus), parvovirus B19 and HIV.
- Sometimes, cancer from another part of the body can spread to the bone marrow and cause aplastic anemia.
Hereditary Aplastic Anemia
Hereditary aplastic anemia is passed down through the genes from parent to child. It is usually diagnosed in childhood and is much less common than acquired aplastic anemia. People who develop hereditary aplastic anemia usually have other genetic or developmental abnormalities that cause the aplastic anemia.
Some inherited conditions can damage stem cells and lead to aplastic anemia, including:
- Fanconi anemia
- Shwachman-Diamond syndrome
- Dyskeratosis (DIS-ker-ah-TO-sis) congenita
- Diamond-Blackfan anemia.
A newly discovered type of hereditary aplastic anemia is due to excessive shortening of the ends of chromosomes, called telomeres. This is usually diagnosed in adults. Family members of the patient may have a history of aplastic anemia or scarring (fibrosis) of the lungs or liver. This type of aplastic anemia can only be diagnosed with special tests.
Inherited Bone Marrow Failure Syndrome Resources
If you are interested in learning more about inherited bone marrow failure syndromes, the resources below may be of help:
- Dyskeratosis Congenita Outreach: a Telomere Biology Disorder
- The Diamond Blackfan Anemia Foundation, Inc. (DBAF)
- Shwachman Diamond Syndrome Foundation
- Fanconi Anemia Research Fund, Inc.
You may also want to visit the National Cancer Institute's (NCI) inherited bone marrow failure syndromes web page. The NCI is also conducting an inherited bone marrow failure syndrome study.