Fanconi anemia complementation group A
What is Fanconi Anemia Complementation Group A?
Fanconi anemia is a group of inherited disorders in which the body cannot properly produce a protein that protects DNA from damage. The defective protein results in an impaired ability of bone marrow to produce all types of blood cells. Without a sufficient number of red blood cells, the body does not receive enough oxygen, which can lead to abnormal bones and organs, as well as developmental delay. Similarly, a shortage of white blood cells makes the body more susceptible to infection and cancer, and a reduction in blood platelets make it difficult for the blood to clot when an injury arises.
Individuals with Fanconi anemia are typically born with some kind of physical abnormality with the most common being short stature, thumb or finger malformation, skin discoloration, kidney and eye anomalies, and skeletal irregularities. However, 25 to 40% of people with the condition do not have physical abnormalities. Thus, individuals may be first diagnosed in childhood with abnormally low levels of red blood cells, white blood cells, or platelets caused by bone marrow failure (because it is progressive most individuals will have some blood-related complication), hearing loss (10% of individuals), some degree of developmental delay (10% of individuals), and/or cancer.
The higher than average risk for cancer stems from the cells' inability to repair themselves when the DNA is damaged. Occasionally, the initial signs of leukemia appear in childhood as the first symptom of the disease. Other cancers may also appear at an unusually early age, particularly tumors of the head and neck, esophagus, cervix, vulva (external opening of the vagina), or liver.
How common is Fanconi Anemia Complementation Group A?
Fanconi anemia type A is the most common type of Fanconi anemia, making up between 60-70% of all cases and affecting approximately 1 in 200,000 people. However, incidence of the condition and the number of cases attributed to FANCA vary in certain ethnic groups due to founder effects (high frequency of disease because the group arose from a small, possibly isolated population). Founder effects have been noted in individuals of Sephardic Jewish descent (Moroccan and Indian), Tunisian descent, Afrikaners, Brazilians, Spanish Gypsies, and others.
How is Fanconi Anemia Complementation Group A treated?
There is currently no cure for Fanconi anemia type A. Treatment consists of monitoring for symptoms and treating them as they appear.
Roughly half of all people with the condition can improve their blood cell counts with medication. Over a period of years, however, people often develop resistance to the medication. Treatment with medication may also decrease the effectiveness of a later bone marrow transplant.
Bone marrow transplantation can cure leukemia associated with Fanconi anemia type A. However people with the condition are extremely sensitive to the chemotherapy and the radiation treatment necessary to prepare for transplantation, so they may not be good candidates for this surgery. A bone marrow transplant does not prevent solid tumors elsewhere in the body, which must be treated with chemotherapy and radiation.
People with Fanconi anemia type A must undergo regular blood cell count tests, bone marrow biopsies, liver scans, and gynecological, dental, and rectal exams to detect early-stage cancers so they can be removed as soon as possible.
What is the prognosis for a person with Fanconi Anemia Complementation Group A?
The prognosis for a person with the disease is dependent upon the severity of the symptoms, which will be variable from person to person.